Cpp

io優化

cin.tie(0);
ios_base::sync_with_stdio(false);

String

int to string
.to_string()
32位元int to binary string
stoi()``string a2 = bitset<32>(a).to_string();

Vector

vector<int> v(10, 1); // create vector 10 slots value 1
vector<int> v[10];    // create vector 10 blank slots
v.erase(v.begin()+i);
v.erase(v.begin()+i, v.begin()+j);

Priority Queue

priority_queue<資料型態> pq;
priority_queue<int, vector<int>, greater<int>> pq;    // 最小優先
priority_queue<int> pq2(pq); // 宣告 pq2 並賦予 pq 的內容

pqpush(val);
pq.pop(); // delete but no return
bool isEmpty = pq.empty(); // check if is empty
pq.size(); // return length

// read each item in pq
while( !pq.empty() ){
    int val = pq.top();
    cout<< val << ' ';
    pq.pop();
}

// use this is a the type of your comparator
typedef std::function<bool(int, int)> comp_type;

// priority queue using operator < for ordering
priority_queue<int, vector<int>, comp_type> first(std::less<int>());

// priority queue using operator > for ordering
priority_queue<int, vector<int>, comp_type> second(std::greater<int>());