<h1 class = "text-style">
SES0
</h1>
<div style="color:green; font-size:150%;"><b>Challenge accepted</b></div>
---
>**By NPDang**
---
<h1 class = "text-style">
Bà i táºp
</h1>
<font size="5" color="cyan"><b>800-Elo Problems</b></font>
:::spoiler <b>4A - Watermelon</b>
---
https://codeforces.com/problemset/problem/4/A
---
---
```c=
#include<stdio.h>
int main()
{
int x;
scanf("%d",&x);
printf(x>2&&x%2==0?"YES":"NO");
}
```
---
<h1>
Giải thÃch
</h1>
---
:::
:::spoiler <b>231A - Team</b>
---
https://codeforces.com/problemset/problem/231/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main()
{
int n,br=0,count=0;
bool b;
cin>>n;
for (int i=0; i<n;i++){
cin>>b;
br+=b;
cin>>b;
br+=b;
cin>>b;
br+=b;
count+=(br>=2);
br=0;
}
cout<<count;
}
```
---
:::
:::spoiler <b>71A - Way Too Long Words<b>
---
https://codeforces.com/problemset/problem/71/A
---
---
```cpp=
#include <iostream>
#include <string>
using namespace std;
int main()
{
string str;
int n;
cin>>n;
for (size_t i = 0;i<n;i++)
{
cin>>str;
if (str.length() > 10)
cout<<str[0]<<str.length()-2<<str[str.length()-1]<<'\n';
else
cout<<str<<'\n';
}
}
```
---
:::
:::spoiler <b>A - Bit++</b>
---
codeforces.com/problemset/problem/282/A
---
---
``` cpp=
#include <iostream>
#include <string>
using namespace std;
int main()
{
short n, x = 0;
cin >> n;
string str;
cin.ignore();
for (int i = 0; i < n; i++)
{
getline(cin, str);
if (str.find("++") != string::npos)
x++;
else if (str.find("--") != string::npos)
x--;
}
cout << x;
}
```
---
:::
:::spoiler 158A - Next Round
---
https://codeforces.com/problemset/problem/158/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, k;
cin>>n>>k;
int scores[n];
for (int i=0;i<n;i++){
cin >> scores[i];
}
int gioihan=scores[k-1];
int result=0;
for (int i = 0; i < n; i++){
if (scores[i]>=gioihan&&scores[i]>0){
result++;
}
}
cout << result << endl;
return 0;
}
```
---
:::
:::spoiler 50A - Domino piling
---
https://codeforces.com/problemset/problem/50/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int a,b; cin>>a>>b;
cout<<(a*b)/2;
return 0;
}
```
---
:::
:::spoiler 263A - Beautiful Matrix
---
https://codeforces.com/problemset/problem/263/A
---
---
```cpp=
#include <iostream>
#include <cmath>
using namespace std;
int main() {
int num, result;
for (int i = 1; i <= 5; i++)
{
for (int j=1; j<=5;j++){
cin>>num;
if (num){
result=abs(3-i)+abs(3-j);
cout<<result;
}
}
}
}
```
---
:::
:::spoiler 112A - Petya and Strings
---
https://codeforces.com/problemset/problem/112/A
---
---
```cpp=
#include <iostream>
#include <string>
#include <cctype>
using namespace std;
int main() {
string str,str2;
cin>>str>>str2;
for(int i =0; i<str.length();i++){
if (tolower(str.at(i))!=tolower(str2.at(i)))
{
cout<<(tolower(str.at(i))>tolower(str2.at(i))?1:-1);
return 0;
}
}
cout<<0;
}
```
---
:::
:::spoiler 339A - Helpful Maths
---
https://codeforces.com/problemset/problem/339/A
---
---
```cpp=
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
string str;
cin>>str;
int countnum;
vector<int> num;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j<(countnum=count(str.begin(),str.end(),char(49+i))); j++)
{
num.push_back(i+1);
}
}
for (int i=0; i< num.size();i++)
{
(i+1==num.size()?printf("%d",num.at(i)):printf("%d+",num.at(i)));
}
}
```
---
:::
:::spoiler 236A - Boy or Girl
---
https://codeforces.com/problemset/problem/236/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
vector<char> array(26,0);
char ch;
while ((ch=getchar())!=EOF)
{
if (ch<'a')
{
break;
}
array.at(ch-'a')|=1;
}
cout<<(count(array.begin(),array.end(),1)%2==0?"CHAT WITH HER!":"IGNORE HIM!");
}
```
---
:::
:::spoiler 281A - Word Capitalization
---
https://codeforces.com/problemset/problem/281/A
---
---
```cpp=
#include <iostream>
#include <cctype>
#include <string>
using namespace std;
int main() {
string str;
cin>>str;
cout<<(str.at(0)<=90?str.at(0):str.at(0)-=32)<<str.substr(1);
}
```
---
:::
:::spoiler 791A - Bear and Big Brother
---
https://codeforces.com/problemset/problem/791/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int a,b;
cin>>a>>b;
for (int y = 1;; y++)
{
a*=3;
b*=2;
if (a>b)
{
cout<<y;
break;
}
}
}
```
---
:::
:::spoiler 266A - Stones on the Table
---
https://codeforces.com/problemset/problem/266/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
int temp;
cin >> temp;
cin >> ws;
vector<char> ch;
for (int i = 0; i < temp; i++) {
ch.push_back(getchar());
}
ch.resize(distance(ch.begin(),unique(ch.begin(),ch.begin()+temp)));
cout<<temp-ch.size();
}
```
---
:::
:::spoiler 617A - Elephant
---
https://codeforces.com/problemset/problem/791/A
---
---
```cpp=
#include <iostream>
#include <cmath>
using namespace std;
int main() {
int d;
cin >> d;
cout<<d/5+(d%5==0?0:1);
}
```
---
:::
:::spoiler 546A - Soldier and Bananas
---
https://codeforces.com/problemset/problem/546/A
---
---
```cpp=
#include <iostream>
#include <cmath>
using namespace std;
int main() {
int n,k,w,res;
cin >> k>> n>> w;
res=n-k*((w+1) * floor(w/2)+(w%2==0?0:floor(w/2+1)));
cout<<(res>=0?0:abs(res));
}
```
---
:::
:::spoiler 59A - Word
---
https://codeforces.com/problemset/problem/59/A
---
---
```cpp=
#include <iostream>
#include <cctype>
#include <algorithm>
using namespace std;
int main() {
string str;
cin>>str;
int lowcount=count_if(str.begin(),str.end(),[](const char &ch){
return islower(ch);});
int uppcount=count_if(str.begin(),str.end(),[](const char &ch){
return isupper(ch);});
if(uppcount>lowcount){
for_each(str.begin(),str.end(),[](const char &ch){
cout<<char(toupper(ch));
});
}
else{
for_each(str.begin(),str.end(),[](const char &ch){
cout<<char(tolower(ch));
});
}
}
```
---
:::
:::spoiler 977A - Wrong Subtraction
---
https://codeforces.com/problemset/problem/977/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int a,b;
cin>>a>>b;
for (int i = 0; i < b; i++)
{
a=(a%10==0?a/10:a-1);
}
cout<<a;
}
```
---
:::
:::spoiler 110A - Nearly Lucky Number
---
https://codeforces.com/problemset/problem/110/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int a;
string str;
cin>>str;
a=count_if(str.begin(),str.end(),[](const char &ch){
return ch=='7'||ch=='4';
});
cout<<(7==a||4==a?"YES":"NO");
}
```
---
:::
:::spoiler 734A - Anton and Danik
---
https://codeforces.com/problemset/problem/734/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int a,length;
cin>>length;
string str;
cin>>str;
a=count(str.begin(),str.end(),'A');
cout<<(a>(length-a)?"Anton":(a==length-a)?"Friendship":"Danik");
}
```
---
:::
:::spoiler 41A - Translation
---
https://codeforces.com/problemset/problem/41/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
string str, str2;
cin>>str>>str2;
reverse(str.begin(),str.end());
cout<<(str==str2?"YES":"NO");
}
```
---
:::
:::spoiler 2094A - Trippi Troppi
---
https://codeforces.com/problemset/problem/2094/A
---
---
```cpp
#include <iostream>
using namespace std;
int main() {
string str;
int a;
cin>>a;
cin.ignore();
for(int i=0; i<a;i++){
getline(cin,str);
cout<<str.at(0);
for(int i=1; i<str.length();i++){
if (str.at(i)==' ')
{
cout<<str.at(i+1);
}
}
cout<<'\n';
}
}
```
---
:::
:::spoiler 677A - Vanya and Fence
---
https://codeforces.com/contest/677/problem/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n,temp,h,count=0;
cin>>n>>h;
for (int i = 0; i < n; i++)
{
cin>>temp;
count+=(temp>h?2:1);
}
cout<<count;
}
```
---
:::
:::spoiler 116A - Tram
---
https://codeforces.com/problemset/problem/116/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n,max=0, a,b,current=0;
cin>>n;
for (int i = 1; i < n; i++)
{
cin>>a;
cin>>b;
current=current-a+b;
max=(current>max?current:max);
}
cout<<max;
}
```
---
:::
:::spoiler 271A - Beautiful Year
---
https://codeforces.com/problemset/problem/271/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int y;
cin>>y;
for (;;)
{
y++;
int temp1=y%10,temp2=y/100%10;
if (temp2!=y/10%10&&temp1!=y/10%10&&temp2!=y/1000&&temp1!=temp2&&temp1!=y/1000&&y/10%10!=y/1000%10&&y/100%10!=temp1)
{
break;
}
}
cout<<y;
}
```
---
:::
:::spoiler 1030A - In Search of an Easy Problem
---
https://codeforces.com/problemset/problem/1030/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n,temp;
cin>>n;
for (int i=0;i<n;i++)
{
cin>>temp;
if (temp)
{
cout<<"HARD";
return 0;
}
}
cout<<"EASY";
return 0;
}
```
---
:::
:::spoiler 266B - Queue at the School
---
https://codeforces.com/problemset/problem/266/B
---
---
```cpp=
#include <iostream>
#include <string>
using namespace std;
int main() {
int n,t;
cin>>n>>t;
string str;
cin>>str;
for (int time = 0; time < t; ++time){
for (int i = 0; i < n - 1; ++i){
if (str[i]=='B'&&str[i+1]=='G') {
swap(str[i], str[i + 1]);
++i;
}
}
}
cout << str;
return 0;
}
```
---
:::
:::spoiler 467A - George and Accommodation
---
https://codeforces.com/problemset/problem/467/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, max, count=0, cur;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> cur >> max;
if (max - cur >= 2)
{
count ++;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 344A - Magnets
---
https://codeforces.com/problemset/problem/344/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
string str,cur="";
int n, count=0;
cin >> n;
for (int i = 0; i < n; i++)
{
cin>>str;
if (cur != str)
{
cur = str;
count ++;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 486A - Calculating Function
---
https://codeforces.com/problemset/problem/486/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
long long n;
cin >> n;
cout << (n % 2 == 1?(n/2) *-1 - 1 : n/2);
return 0;
}
```
---
:::
:::spoiler 136A - Presents
---
https://codeforces.com/problemset/problem/136/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
int f[n];
for (int i = 0; i < n; i++)
{
int temp;
cin >> temp;
f[temp-1] = i + 1;
}
for (const int &i : f)
{
cout<<i<<' ';
}
return 0;
}
```
---
:::
:::spoiler 200B - Drinks
---
https://codeforces.com/problemset/problem/200/B
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
double result;
short n;
cin >> n;
for (int i = 0; i < n; i++)
{
int temp;
cin >> temp;
result += temp;
}
cout<<result/n;
}
```
---
:::
:::spoiler 228A - Is your horseshoe on the other hoof?
---
https://codeforces.com/problemset/problem/228/A
---
---
```cpp=
#include <iostream>
#include <set>
using namespace std;
int main() {
int temp = 0;
set <int> arr;
for (int i = 0; i < 4; i++)
{
cin >> temp;
arr.insert(temp);
}
cout << 4 - arr.size();
}
```
---
:::
:::spoiler 61A - Ultra-Fast Mathematician
---
https://codeforces.com/problemset/problem/61/A
---
---
```cpp=
#include <iostream>
#include <string>
using namespace std;
int main() {
string str1, str2;
cin >> str1 >> str2;
for (int i = 0; i < str1.length(); i++)
{
if ( (str1[i] == '1'|| str2[i] == '1') && str1[i] != str2[i])
{
cout << '1';
}
else{
cout << '0';
}
}
return 0;
}
```
---
:::
:::spoiler 705A - Hulk
---
https://codeforces.com/problemset/problem/705/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int lay;
cin >> lay;
for (int i = 0; i < lay; i++)
{
if (i % 2 == 0){
cout << "I hate ";
}
else{
cout << "I love ";
}
if (i+1==lay)
{
cout << "it ";
}
else{
cout << "that ";
}
}
return 0;
}
```
---
:::
:::spoiler 1328A - Divisibility Problem
---
https://codeforces.com/problemset/problem/1328/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, a, b;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a >> b;
if (a/b * b != a)
{
cout << (a/b + 1) * b - a << '\n';
}
else{
cout << 0 << '\n';
}
}
return 0;
}
```
---
:::
:::spoiler 520A - Pangram
---
https://codeforces.com/problemset/problem/520/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
string str;
int n;
vector <int> alp(26);
cin >> n >> str;
if (str.length() < 26)
{
cout << "NO";
}
else{
for (const char &ch : str){
alp[tolower(ch) - 97] ++;
}
if (count(alp.begin(), alp.end(), 0) != 0)
{
cout << "NO";
}
else cout << "YES";
}
return 0;
}
```
---
:::
:::spoiler 469A - I Wanna Be the Guy
---
https://codeforces.com/problemset/problem/469/A
---
---
```cpp=
#include <iostream>
#include <set>
using namespace std;
int main() {
set <int> lvs;
int n;
cin >> n;
for (int i = 0; i < 2; ++i){
int j;
cin >> j;
for (j; j>0; --j)
{
int temp;
cin >> temp;
lvs.insert(temp);
}
}
cout << (lvs.size() == n ? "I become the guy." : "Oh, my keyboard!");
return 0;
}
```
---
:::
:::spoiler 144A - Arrival of the General
---
https://codeforces.com/problemset/problem/144/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n;
cin >> n;
int arr[n];
for (int i = 0; i < n; i++){
int temp;
cin >> temp;
arr[i] = temp;
}
int *mp=max_element(arr, arr + n);
int minVal = *min_element(arr, arr + n);
int *np = arr + n - 1;
while (*np != minVal) {
--np;
}
if ( np < mp )
{
cout << distance(arr, mp) + distance(np, arr + n - 1) - 1;
}
else{
cout << distance(arr, mp) + distance(np, arr + n - 1);
}
return 0;
}
```
---
:::
:::spoiler 996A - Hit the Lottery
---
https://codeforces.com/problemset/problem/996/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int m, count = 0, opt[5] = {1, 5, 10, 20, 100};
cin >> m;
for (int i = 0; i < 5; i++){
while (m >= opt[4 - i] && m > 0)
{
m -= opt[4 - i];
count ++;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 148A - Isomina cure
---
https://codeforces.com/contest/148/problem/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int k, m, l, d, n, count = 0;
cin >> k >> l >> m >> n >> d;
for (int i = 1; i <= d; i ++){
count += (i % k == 0 || i % l == 0 || i % m == 0 || i % n == 0);
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 443A - Anton and Letters
---
https://codeforces.com/problemset/problem/443/A
---
---
```cpp=
#include <iostream>
#include <set>
using namespace std;
int main() {
char ch;
set<char> str;
ch = getchar();
while ((ch = getchar()) != EOF)
{
if (isalpha(ch)){
str.insert(ch);
}
}
cout << str.size();
return 0;
}
```
---
:::
:::spoiler 785A - Anton and Polyhedrons
---
https://codeforces.com/problemset/problem/785/A
---
---
```cpp=
#include <iostream>
#include <set>
using namespace std;
int main() {
int n, count = 0;
string str;
cin >> n;
cin.ignore();
for (int i = 0;i < n; i++){
getline(cin, str);
switch (str[0])
{
case 'C':
count += 6;
break;
case 'T':
count += 4;
break;
case 'O':
count += 8;
break;
case 'D':
count += 12;
break;
default:
count += 20;
break;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 268A - Games
---
https://codeforces.com/problemset/problem/268/A
---
---
```cpp=
#include <iostream>
#include <vector>
using namespace std;
int main() {
int n, count = 0;
cin >> n;
vector<int> home(n), away(n);
for (int i = 0; i < n; ++i)
cin >> home[i] >> away[i];
for (int i = 0; i < n; ++i) {
for (int j = 0; j < n; ++j) {
if (i != j && home[i] == away[j])
++count;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 1335A - Candies and Two Sisters
---
https://codeforces.com/problemset/problem/1335/A
---
---
```cpp=
#include <iostream>
#include <cmath>
using namespace std;
int main() {
long t, c, count = 0;
cin >> t;
for (int i = 0; i < t; i++)
{
cin >> c;
cout << fixed << int(round(double(c)/2) - 1);
if (i + 1 == t) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 510A - Fox And Snake
---
https://codeforces.com/problemset/problem/510/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int a, b;
cin >> a >> b;
for (int i = 0; i < a; i++){
switch (i % 4)
{
case 1:
for (int i = 0; i < b - 1; i++)
{
cout << '.';
}
cout << '#';
break;
case 3:
cout << '#';
for (int i = 0; i < b - 1; i++)
{
cout << '.';
}
break;
default:
for (int i = 0; i < b; i++)
{
cout << '#';
}
break;
}
if (i + 1 == a) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 141A - Amusing Joke
---
https://codeforces.com/problemset/problem/141/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int luabovaochuong[26] = {0};
char ch;
for (int i = 0; i < 2; i++)
{
while ((ch = getchar()) != '\n')
{
luabovaochuong[ch - 'A'] ++;
}
}
while ((ch = getchar()) != EOF)
{
luabovaochuong[ch - 'A']--;
}
cout << (count(luabovaochuong, luabovaochuong + 26, 0) == 26? "YES" : "NO");
return 0;
}
```
---
:::
:::spoiler 1352A - Sum of Round Numbers
---
https://codeforces.com/problemset/problem/1352/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
int n;
cin >> n;
for (int i = 0; i < n; i++){
int temp;
cin >> temp;
vector <int> slices;
int base = 1;
while (temp > 0)
{
int di = temp % 10;
if (di != 0) slices.push_back(di * base);
temp /= 10;
base *= 10;
}
cout << slices.size() << '\n';
for (const int &i : slices){
cout << i << ' ';
}
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 723A - The New Year: Meeting Friends
---
https://codeforces.com/problemset/problem/723/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n[3];
cin >> n[0];
cin >> n[1];
cin >> n[2];
sort(n, n+3);
cout << n[1]-n[0] + n[2]-n[1];
return 0;
}
```
---
:::
:::spoiler 1742A - Sum
---
https://codeforces.com/problemset/problem/1742/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int s, n[3];
cin >> s;
for (int i = 0; i < s; i++){
cin >> n[0] >> n[1] >> n[2];
sort(n, n+3);
cout << (n[1]+n[0]==n[2] ? "YES" : "NO");
if (i + 1 == s) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 427A - Police Recruits
---
https://codeforces.com/problemset/problem/427/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n, count = 0, temp, policers = 0;
cin >> n;
for (int i = 0; i < n; i ++){
cin >> temp;
if (policers == 0 && temp == -1) count ++;
else policers += temp;
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 750A - New Year and Hurry
---
https://codeforces.com/problemset/problem/750/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int MAX = 240, a, b, base = 5, spent = 0;
cin >> a >>b;
int remain = MAX - b;
for (int i = 1; i < a + 1; i++){
spent += base*i;
if (remain < spent){
cout << i - 1;
return 0;
}
}
cout << a;
return 0;
}
```
---
:::
:::spoiler 155A - I_love_\%username\%
---
https://codeforces.com/problemset/problem/155/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, temp, max, min, count = 0;
cin >> n >> max;
min = max;
for (int i = 1; i < n; i++){
cin >> temp;
if (max < temp){
count++;
max = temp;
}
else if (min > temp){
count++;
min = temp;
}
}
cout << count;
return 0;
}
```
---
:::
:::spoiler 151A - Soft Drinking
---
https://codeforces.com/problemset/problem/151/A
---
---
```cpp=
#include <iostream>
#include <set>
using namespace std;
int main() {
int f, b, bl, c, cd, p, nb, np;
cin >> f >> b >> bl >> c >> cd >> p >> nb >> np;
set <int> amount;
amount.insert(b * bl/nb);
amount.insert(c * cd);
amount.insert(p / np);
cout << *amount.begin()/f;
return 0;
}
```
---
:::
:::spoiler 1703A - YES or YES?
---
https://codeforces.com/problemset/problem/1703/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
char ch[4];
for (int i = 0; i < n; i++){
cin >> ch;
if (tolower(ch[0]) != 'y' || tolower(ch[1]) != 'e' || tolower(ch[2]) != 's') cout << "NO";
else cout << "YES";
if (i + 1 == n) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 732A - Buy a Shovel
---
https://codeforces.com/problemset/problem/732/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int s, b, i = 1;
cin >> s >> b;
while ((s * i - b) % 10 != 0 && s * i % 10 != 0){
i ++;
}
cout << i;
return 0;
}
```
---
:::
:::spoiler 630A - Again Twenty Five!
---
https://codeforces.com/problemset/problem/630/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
cout << 25;
return 0;
}
```
---
:::
:::spoiler 1154A - Restoring Three Numbers
---
https://codeforces.com/problemset/problem/1154/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int list[4];
cin >> list[0] >> list[1] >> list[2] >> list[3];
sort(list, list + 4);
cout << list[3] - list[0] << ' ' << list[3] - list[1] << ' ' << list[3] - list[2];
return 0;
}
```
---
:::
:::spoiler 581A - Vasya the Hipster
---
https://codeforces.com/problemset/problem/581/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int a, b;
cin >> a >> b;
if (a > b) cout << b << ' ' << (a - b) /2;
else cout << a <<' ' << (b - a) / 2;
return 0;
}
```
---
:::
:::spoiler 381A - Sereja and Dima
---
https://codeforces.com/problemset/problem/381/A
---
---
```cpp=
#include <iostream>
#include <deque>
using namespace std;
int main() {
int n, temp;
cin >> n;
deque<int> list;
for (int i = 0; i < n; i++)
{
cin >> temp;
list.push_back(temp);
}
int sum1 = 0, sum2 = 0;
for (int i = 0; i < n; i++)
{
temp = (list.front() > list.back() ? list.front() : list.back());
(i % 2 == 0 ? sum1 : sum2) += temp;
if (temp == list.front()) list.pop_front();
else list.pop_back();
}
cout << sum1 << ' ' << sum2;
return 0;
}
```
---
:::
:::spoiler 1669A - Division?
---
https://codeforces.com/problemset/problem/1669/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, ranking;
cin >> n;
for (int i = 0; i < n; i++){
cin >> ranking;
cout << "Division ";
if (ranking >= 1900) cout << "1";
else if (ranking >= 1600) cout << '2';
else if (ranking >= 1400) cout << "3";
else cout << "4";
if (i + 1 == n) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1692A - Marathon
---
https://codeforces.com/problemset/problem/1692/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int temp, n, list[4];
cin >> n;
for (int i = 0; i < n; i++){
cin >> temp;
list[0] = temp;
for (int j = 1; j < 4; j++)
{
cin >> list[j];
}
sort(list, list + 4);
cout << distance(find(list, list + 4, temp), list + 4) - 1;
if (i + 1 == n) continue;
cout <<'\n';
}
return 0;
}
```
---
:::
:::spoiler 1676A - Lucky?
---
https://codeforces.com/problemset/problem/1676/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, sum1 = 0, sum2 = 0;
cin >> n;
cin.ignore();
for (int i = 0; i < n; i++){
sum1 += (_getchar_nolock() - '0');
sum1 += (_getchar_nolock() - '0');
sum1 += (_getchar_nolock() - '0');
sum2 += (_getchar_nolock() - '0');
sum2 += (_getchar_nolock() - '0');
sum2 += (_getchar_nolock() - '0');
if (sum1 == sum2) cout << "YES";
else cout << "NO";
sum1 = sum2 = 0;
if (i + 1 == n) continue;
cout << '\n';
_getchar_nolock();
}
return 0;
}
```
---
:::
:::spoiler 1676A - Lucky?
---
https://codeforces.com/problemset/problem/1807/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, a, b, c;
cin >> n;
while (n--)
{
cin >> a >> b >> c;
if (c == b + a) cout << '+';
else cout << '-';
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1409A - Yet Another Two Integers Problem
---
https://codeforces.com/problemset/problem/1409/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, a, b;
cin >> n;
while (n--){
cin >> a >> b;
if (a == b) cout << 0;
else {
cout << abs(b - a) / 10 + ( (b-a) % 10 != 0);
}
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 2065A - Skibidus and Amog'u
---
https://codeforces.com/problemset/problem/2065/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
string str;
int n;
cin >> n;
while (n--){
cin >> str;
cout << str.substr(0, str.length() - 2) + 'i';
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1399A - Remove Smallest
---
https://codeforces.com/problemset/problem/1399/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
int main(){
int t;
std::cin >> t;
while (t--) {
int n;
std::cin >> n;
std::vector<int> a(n);
for (int i = 0; i < n; ++i) {
std::cin >> a[i];
}
std::sort(a.begin(), a.end());
bool possible = true;
for (int i = 0; i < n - 1; ++i) {
if (a[i+1] - a[i] > 1) {
possible = false;
break;
}
}
if (possible) {
std::cout << "YES\n";
} else {
std::cout << "NO\n";
}
}
return 0;
}
```
---
:::
:::spoiler 2114A - Square Year
---
https://codeforces.com/problemset/problem/2114/A
---
---
```cpp=
#include <iostream>
#include <cmath>
using namespace std;
int main(){
int n, y;
cin >> n;
while (n--)
{
cin >> y;
int res = int(sqrt(y));
if (res * res == y) cout << res << ' ' << 0;
else cout << -1;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 2044A - Easy Problem
---
https://codeforces.com/problemset/problem/2044/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, y;
cin >> n;
while (n--)
{
cin >> y;
cout << y - 1;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 2044A - Easy Problem
---
https://codeforces.com/contest/1985/problem/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n;
string y;
cin >> n;
cin.ignore();
while (n--)
{
getline(cin, y);
cout << y[4] << y.substr(1,2) << ' ' << y[0] << y.substr(5,2);
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1999A - A+B Again?
---
https://codeforces.com/problemset/problem/1999/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, y;
cin >> n;
cin.ignore();
while (n--)
{
cin >> y;
cout << y % 10 + y / 10;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 32B - Borze
---
https://codeforces.com/problemset/problem/32/B
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
char temp;
while ((temp = _getchar_nolock()) != EOF)
{
if (temp == '.') cout << 0;
else if (temp == '-')
{
temp = _getchar_nolock();
if (temp == '.') cout << 1;
else cout << 2;
}
}
return 0;
}
```
---
:::
:::spoiler 1512A - Spy Detected!
---
https://codeforces.com/problemset/problem/1512/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
int n; cin >> n;
while (n --){
int size;
cin >> size;
vector<int> nums(size);
for (int i = 0; i < size; i ++){
cin >> nums[i];
}
vector<int> nums2 = nums;
sort(nums.begin(),nums.end());
if (nums[1] == nums.front()) cout << distance(nums2.begin(),find(nums2.begin(),nums2.end(), nums.back()) + 1);
else cout << distance(nums2.begin(),find(nums2.begin(),nums2.end(), nums.front()) + 1);
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1791A - Codeforces Checking
---
https://codeforces.com/problemset/problem/1791/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n; cin >> n;
string cf = "codeforces";
cin.ignore();
while (n --){
char ch = _getchar_nolock();
if (find(cf.begin(), cf.end(), ch) != cf.end()) cout << "YES";
else cout << "NO";
if (n == 0) continue;
_getchar_nolock();
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1760A - Medium Number
---
https://codeforces.com/problemset/problem/1760/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int a, b, c, n;
cin >> n;
while (n--)
{
cin >> a >> b >> c;
if ((a < b && b < c ) || (c < b && b < a)) cout << b;
else if ((a < c && c < b) || (b < c && c < a)) cout << c;
else cout << a;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1915A - Odd One Out
---
https://codeforces.com/problemset/problem/1915/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int a, b, c, n;
cin >> n;
while (n--)
{
cin >> a >> b >> c;
cout << (a ^= b ^= c);
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 758A - Holiday Of Equality
---
https://codeforces.com/problemset/problem/758/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int temp, n, max = 0, sum = 0;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> temp;
sum += temp;
max = (max < temp ? temp : max);
}
cout << max * (n - 1) -(sum - max);
return 0;
}
```
---
:::
:::spoiler
---
https://codeforces.com/problemset/problem/1560/A
---
---
```cpp=
#include <iostream>
#include <vector>
using namespace std;
int main(){
vector <int> list;
int cur = 1;
while (list.size() < 1000) {
if (cur % 3 != 0 && cur % 10 != 3) {
list.push_back(cur);
}
cur++;
}
int n;
cin >> n;
while (n--) {
int k;
cin >> k;
cout << list[k - 1] << '\n';
}
return 0;
}
```
---
:::
:::spoiler 472A - Design Tutorial: Learn from Math
---
https://codeforces.com/problemset/problem/472/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n;
cin >> n;
if (n % 2 == 0) cout << n - 8 << ' ' << 8;
else cout << n - 9 << ' ' << 9;
return 0;
}
```
---
:::
:::spoiler 1850A - To My Critics
---
https://codeforces.com/problemset/problem/1850/A
---
---
```cpp=
#include <iostream>
#include <vector>
using namespace std;
int main(){
int n, a, b, c;
cin >> n;
while (n--)
{
cin >> a >> b >> c;
if (a + b >= 10 || b + c >= 10 || a + c >= 10) cout << "YES";
else cout << "NO";
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 432A - Choosing Teams
---
https://codeforces.com/problemset/problem/432/A
---
---
```cpp=
#include <iostream>
#include <vector>
using namespace std;
int main(){
int n, t, count = 0;
cin >> n >> t;
vector<int> p(n);
for (int i = 0; i < n; i ++){
cin >> p[i];
}
for (const int & i : p){
if (i + t <= 5) count++;
}
cout << count / 3;
return 0;
}
```
---
:::
:::spoiler 490A - Team Olympiad
---
https://codeforces.com/problemset/problem/490/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
int n, t, count = 0;
cin >> n;
vector <int> PE, Code, Mat;
for (int i = 1; i <= n; i++)
{
cin >> t;
if (t == 1) Code.push_back(i);
else if(t == 2) Mat.push_back(i);
else PE.push_back(i);
}
int gmin = min({Code.size(),Mat.size(),PE.size()});
cout << gmin << '\n';
for (int i = 0; i < gmin; i++){
cout << Code.at(i) << ' ' << Mat.at(i) << ' ' << PE.at(i);
if (i + 1 == gmin) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1899A - Game with Integers
---
https://codeforces.com/problemset/problem/1899/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, t;
cin >> n;
while(n--){
cin >> t;
cout << (t % 3 == 0 ? "Second": "First");
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 9A - Die Roll
---
https://codeforces.com/problemset/problem/9/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int t, t2;
cin >> t >> t2;
if (t > t2){
t ^= t2;
t2 ^= t;
t ^= t2;
}
int rem = 6 - t2 + 1;
int g = __gcd(rem, 6);
rem /= g;
cout << rem << '/' << 6/g;
return 0;
}
```
---
:::
:::spoiler 2009A - Minimize!
---
https://codeforces.com/problemset/problem/2009/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main(){
int n, a, b;
cin >> n;
while (n--)
{
cin >> a >> b;
cout << -a + b;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1873A - Short Sort
---
https://codeforces.com/problemset/problem/1873/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n, count = 2;
string str;
cin >> n;
while (n--)
{
cin >> str;
for (int i = 0; i < str.length(); i++){
count -= (str.at(i) == i + 97);
}
cout << (count > 1 ? "NO" : "YES");
count = 2;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1367A - Short Substrings
---
https://codeforces.com/problemset/problem/1367/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n;
string str;
cin >> n;
while (n--)
{
cin >> str;
for (int i = 0; i < str.length(); i++)
{
if (i % 2 == 0) cout << str.at(i);
}
cout << str.back();
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1950A - Stair, Peak, or Neither?
---
https://codeforces.com/problemset/problem/1950/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n, a, b, c;
cin >> n;
while (n--)
{
cin >> a >> b >> c;
if (c > b && b > a) cout << "STAIR";
else if (c < b && a < b) cout << "PEAK";
else cout << "NONE";
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 703A - Mishka and Game
---
https://codeforces.com/problemset/problem/703/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n, a, b, count1 = 0, count2 = 0;
cin >> n;
while (n--)
{
cin >> a >> b;
count1 += (a > b);
count2 += (b > a);
}
cout << (count1 > count2 ? "Mishka" : (count1 == count2 ? "Friendship is magic!^^" : "Chris"));
return 0;
}
```
---
:::
:::spoiler 1829A - Love Story
---
https://codeforces.com/problemset/problem/1829/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int n, count = 0;
string str;
const string cf = "codeforces";
cin >> n;
while (n--)
{
cin >> str;
for (int i = 0; i < str.length(); i++){
if (str.at(i) != cf.at(i)) count ++;
}
cout << count;
count = 0;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1343B - Balanced Array
---
https://codeforces.com/problemset/problem/1343/B
---
---
```cpp=
#include <iostream>
#include <vector>
int main() {
int t;
std::cin >> t;
while (t--) {
int n;
std::cin >> n;
if ((n / 2) % 2 != 0) {
std::cout << "NO\n";
} else {
std::cout << "YES\n";
std::vector<long long> a(n);
long long sum_even = 0;
for (int i = 0; i < n / 2; ++i) {
a[i] = (i + 1) * 2;
sum_even += a[i];
}
long long sum_odd = 0;
for (int i = 0; i < n / 2 - 1; ++i) {
a[n / 2 + i] = (i * 2) + 1;
sum_odd += a[n / 2 + i];
}
a[n - 1] = sum_even - sum_odd;
for (int i = 0; i < n; ++i) {
std::cout << a[i] << (i == n - 1 ? "" : " ");
}
std::cout << "\n";
}
}
return 0;
}
```
---
:::
:::spoiler 431A - Black Square
---
https://codeforces.com/problemset/problem/431/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int arr[4], sum = 0;
cin >> arr[0] >> arr[1] >> arr[2] >> arr[3];
cin.ignore();
char ch;
while ((ch = _getchar_nolock()) != EOF && ch != '\n')
{
sum += arr[ch - 49];
}
cout << sum;
return 0;
}
```
---
:::
:::spoiler 80A - Panoramix's Prediction
---
https://codeforces.com/problemset/problem/80/A
---
---
```cpp=
#include <iostream>
#include <vector>
using namespace std;
int main() {
int a, n;
cin >> a >> n;
vector<bool> isPrime(n + 1, true);
isPrime[0] = isPrime[1] = false;
for (int p = 2; p * p <= n + 1; p++) {
if (isPrime[p]) {
for (int i = p * p; i <= n + 1; i += p) {
isPrime[i] = false;
}
}
}
int nextPrime = -1;
for (int i = a + 1; i <= n + 1; i++) {
if (isPrime[i]) {
nextPrime = i;
break;
}
}
if (nextPrime == n)
cout << "YES";
else
cout << "NO";
return 0;
}
```
---
:::
:::spoiler 1800A - Is It a Cat?
---
https://codeforces.com/contest/80/problem/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, length, currentcharacter;
bool can = true;
char meow[4]= {'m','e','o','w'};
cin >> n;
while (n--){
cin >> length;
currentcharacter = 0;
string str;
cin >> str;
// duyet qu tung ky tu nek
for (int i = 0; i < length; i ++){
if (char(tolower(str.at(i))) != meow[currentcharacter]){
currentcharacter++;
if (i == 0|| currentcharacter > 3 || char(tolower(str.at(i))) != meow[currentcharacter]){
cout << "NO";
can = false;
break;
}
}
}
if (can && currentcharacter == 3) cout << "YES";
else if (can) cout << "NO";
can = true;
currentcharacter = 0;
if (n == 0) continue;
cout << '\n';
}
return 0;
}
```
---
:::
:::spoiler 1857A - Array Coloring
---
https://codeforces.com/problemset/problem/1857/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
int n;
cin >> n;
while (n--)
{
int size;
vector<int> array;
cin >> size;
for (int i = 0; i < size; i++){
int val;
cin >> val;
array.push_back(val);
}
int even = count_if(array.begin(), array.end(), [](const int &a){
return (a % 2 == 0);
}), odd = size - even;
if (odd % 2 == 0) cout << "YES";
else cout << "NO";
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1829B - Blank Space
---
https://codeforces.com/problemset/problem/1829/B
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n, count = 0, max = 0;
cin >> n;
while (n--)
{
int size;
cin >> size;
while (size --)
{
bool t;
cin >> t;
if (!t) count++;
else if (t) {
max = (count > max ? count : max);
count = 0;
}
}
max = (count > max ? count : max);
cout << max;
max = count = 0;
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1374A - Required Remainder
---
https://codeforces.com/problemset/problem/1374/A
---
---
```cpp=
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n, a, b, n2;
cin >> n;
while (n--)
{
cin >> a >> b >> n2;
if (n2 - n2 % a + b <= n2 ) {
cout << n2 - n2 % a + b;
} else {
cout << n2 - n2 % a - (a - b);
}
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1619A - Square String?
---
https://codeforces.com/problemset/problem/1619/A
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n, can;
cin >> n;
while (n--)
{
string str;
cin >> str;
if (str.length() % 2 == 0){
for (int i = 0; i < str.length()/2; i++){
if (str[i] != str[i + str.length() / 2]) {
can = false;
break;
}
}
}
else can = 0;
if (can) cout << "YES";
else cout << "NO";
can = 1;
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1791C - Prepend and Append
---
https://codeforces.com/problemset/problem/1791/C
---
---
```cpp=
#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
while (n--)
{
string str;
int n2;
cin >> n2 >> str;
int count = n2;
for (int i = 0; i < n2/2; i++){
if (str.at(i) != str.at(n2 - i - 1)){
count-= 2;
}
else break;
}
cout << count;
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1722A - Spell Check
---
https://codeforces.com/problemset/problem/1722/A
---
---
```cpp=
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
int n;
string T = "Trium";
sort(T.begin(), T.end());
cin >> n;
while (n--)
{
string str;
int n2;
cin >> n2 >> str;
sort(str.begin(), str.end());
if (str.length() != 5) cout << "NO";
else if (str == T) cout << "YES";
else cout << "NO";
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
:::spoiler 1433A - Boring Apartments
---
https://codeforces.com/contest/1433/problem/A
---
---
```cpp=
#include <iostream>
using namespace std;
int checkdi (int n){
int di = 0;
while (n > 0)
{
n /= 10;
di ++;
}
return di;
}
int acc(int di){
if (di == 1) return 1;
else return (di + acc(di - 1));
}
int main() {
int n;
cin >> n;
while (n--)
{
int t;
cin >> t;
int di = checkdi(t), base = t % 10;
di = acc(di);
cout << (base - 1) * 10 + di;
if (n == 0) continue;
cout << '\n';
}
}
```
---
:::
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