Computer Programming (I)

# Computer Programming (I) NTNU 程式設計(一) ##### [Back to Note Overview](https://reurl.cc/XXeYaE) ###### tags: `NTNU` `CSIE` `必修` `Programming(I)` ###### Author Team：@kizato @sophie8909 @joseph89108 @AWfulsome @HsuanYu @RuiRabbit @KaoZhai @ShihHeng @Eoleedi ### [Moodle](https://moodle.ntnu.edu.tw/course/view.php?id=19520) ### [Class Web](https://sites.google.com/gapps.ntnu.edu.tw/neokent/teaching/2019fall-computer-programming-i) ### [Homework Sample](##Homework) {%hackmd hackmd-dark-theme %} ## Tips #### 貼網址時請多加善用 [網址縮小燈](https://reurl.cc/main/en) #### 不知道顏色的時候 [色碼查詢器](https://www.ifreesite.com/color/) >**非管理員但願意加入筆記編寫的** > >可在此區留言或直接跟Admin們要Write權限 >給帳號(profile裡@的那串)或email皆可 >所有**登入帳號**都可以在留言區發言 >有問題可以直接留言區留 >**修正注意事項** >麻煩發現**觀念錯誤**的先以~~這種方式~~修改並標上日期提醒其他人 > 錯字類的直接修改即可 --- ## 課堂影片紀錄檔 https://reurl.cc/A1gLZp --- ## Integrated Development Environment * [Visual Studio](https://visualstudio.microsoft.com/downloads/) * 超級肥 [name=AWfulsome] * [Code::Blocks](http://www.codeblocks.org/downloads/26) * 這個還行就是很肥然後預設介面是白的眼睛好痛[name=sophie] * [Dev-C++](http://orwelldevcpp.blogspot.com/) * 這個超難用的啦還很醜用它不如用Sublime [name=sophie] * 以前學校都教這個 [name=HsuanYu] * 我普遍用這種 [name=KaoZhai] * 明明就很好用，內建編譯器雖然舊但還夠用 [name=王麒翔] * [Visual Studio Code](https://code.visualstudio.com/?wt.mc_id=vscom_downloads) * 這個要自己安裝編譯器還要設置環境很複雜，Linux更複雜。[name=蕭瀜] * [Eclipse](https://www.eclipse.org/downloads/) * 我自己印象比較深刻就是它有可以直接視窗化的外掛(windowbuilder)可以用 [name=sophie] * 另外如果有想打競程的NCPC決賽可以用的IDE只有這個跟Netbeans [name=sophie] * 有點肥跑得有點慢但Debug模式不錯用 [name=Joseph Tu] --- ## Text Editor * [SublimeText](https://www.sublimetext.com/3) * 私心大推:heart: 它介面很好看!![name=sophie] * 這個介面真的很好看我沒記錯可以裝像是插件的東西讓你打程式變很快[name=KaoZhai] * 灰底看了就是很舒服還可以多行同時編輯很方便 [name=HsuanYu] * [Vim](https://www.vim.org/download.php) * 老牌文字編輯器，腳本寫得好並善用外掛可以變超強，但我腳本寫不好也不會用外掛... [name=AWfulsome] --- ## Linux ### Use Virtual Box [安裝](https://reurl.cc/jdqj1n) [調整顯示大小](https://reurl.cc/4gy712) ### Use Dual Systems [Win10](https://reurl.cc/EK2MRK) (Mac 沒裝過會怕...還是乖乖用VM就好) ### Terminal ``` ls 展開此目錄下的東西 -a 顯示所有目錄、檔案，包含隱藏的 -l 以列表方式呈現 cd 切換到此目錄(change directory) cd ~ 返回家目錄 cd .. 返回上一層 cd . 回到這一層 gcc 編譯 -o xxx 將編譯後檔案命名為xxx -Wall 顯示所有警告 pwd 顯示目前完整路徑 ./　當前位置 ~/　家目錄位置 rm 刪除檔案 -r 遞迴往下刪 -f 強制刪除 mv 移動檔案 mv A.txt B.txt 將A.txt改名B.txt mkdir 新增目錄 rmdir 刪除目錄 ``` 更多可看[CTF Note](https://hackmd.io/uF8P3o-RTt68JxkhPuryAQ) --- ## 9/18 First coding class ### Code 【Hello World】 ```c= #include <stdio.h> int main(){ // Your first code. printf("Hello World!\n"); return 0; } ``` ### 豆知識 printf 的 "f" 代表 format gcc 在沒有 include stdio.h 時也可以成功編譯 printf gcc 是給 C 用的，C++ 要用 g++ --- ## 9/20 Makefile ### Make 先建一個檔名為"GNUmakefile"or"Makefile" or "makefile"的檔案 ##### 內容： ```make all: gcc -o "你的檔名".c -o "filename" clear: rm "filename" ``` 裡面都可以寫要執行的指令，之後還會有連結檔案。 ### 豆知識 RTFM：read the Fucking manual STFG：search the Fucking google --- ## 9/25 Simple Code ### Code 【Addition】 ```cpp= #include<stdio.h> //Variable int main() { int a = 2;//賦予a 2的數值 int b = 3; int sum = 0; sum = a + b;//先算a+b 之後再賦值給sum printf("sum = %d\n", sum ); return 0; } ``` ### Other code 【Exponential Function】 ```c= #include <stdio.h> #include <math.h> int main () { printf ("7 ^ 3 = %f\n", pow (7.0, 3.0) ); printf ("4.73 ^ 12 = %f\n", pow (4.73, 12.0) ); printf ("32.01 ^ 1.54 = %f\n", pow (32.01, 1.54) ); return 0; } ``` ### Pratice & Answer 請用C寫出 0.5 + 2.7 * 3.2 - 6.8 / 2.4 的答案 ```c= #include <stdio.h> int main() { printf("%f\n", 0.5 + 2.7 * 3.2 - 6.8 / 2.4); return 0; } ``` [wiki_Clang](https://zh.wikipedia.org/zh-tw/Clang) ### Print Format | | 意思 | 宣告 |備註| | -------- | -------- | -------- |--------| | %d | 十進位整數 | int |decimal int| |%i|整數|int|%d and %i are synonymous for output, but are different when used with scanf() for input where using %i will interpret a number as hexadecimal if it's preceded by 0x, and octal if it's preceded by 0| | %f|浮點數|float|如果寫成 %.xf 會只顯示到小數點下第x位，並四捨五入| |%u|無號整數|unsigned int|如果題目不會遇到負數然後最大範圍到2^32^-1的時候可以用| |%c|字元|char|| |%s|字元陣列|char*|| |%%|列印%|------| #### %i using sample ```c= #include <stdio.h> int main() { int a, b, c; //Enter value of a in decimal format scanf("%i", &a); // input 12 //Enter value of b in octal format scanf("%i", &b); // input 012 //Enter value of c in hexadecimal format scanf("%i", &c); // input 0x12; printf("a = %i, b = %i, c = %i", a, b, c); return 0; } // output >> a = 12, b = 10, c = 18 ``` [wiki](https://en.wikipedia.org/wiki/Printf_format_string) --- ## 9/27 Makefile認真看不會就問 ###### (其實真的不懂的話，只要會交作業的make就好了) ### Makefile規則 ``` Target : 目標檔案，格式包含 Object 、執行檔、標籤(Label) Dependency : 產生目標檔案(Target)所需要的檔案 Command : Make 之後執行的命令、每行 Command 需用 Tab 鍵縮排不能用 Space 這是一個文件的依賴關係，target這個目標檔案會依賴於dependency中的文件，其生成規則定義在command中。如果dependency中如果有一個以上的文件比target文件要新的話，command 所定義的命令就會被執行。這是Makefile最核心的內容。 ``` ### 慣用Label ``` all: 置於所有Flag頂端,執行所有編譯(通常為最終目標) clean: 清除所有編譯過程產生的非執行必要檔 info: 產生info檔案 check 或 test: 確認所有檔案已產生 install: 進行安裝指令(編譯後放入安裝路徑) uninstall: 刪除install產生的檔案 ``` ### 預定義變數 ``` CC: C語言編譯器, cc CPP: C語言 / c++編譯器, $(CC) -E CXX: C++語言編譯器 ,g++ CFLAGS: C語言編譯器的編譯選項 CPPFLAGS: C語言前處理器的編譯選項 CXXFLAGS: C++語言編譯器的編譯選項 INCLUDE: 要包含進的函式庫資料夾路徑 srcdir: 需要 compile 的 source code 資料夾路徑 RM: 刪除檔案程式的名稱, rm f ``` ### 偽目標 (.PHONY) ``` .PHONY會將目標檔案射成假目標，使make目錄下沒有目標檔案或目標檔案圍最心時，仍可執行 make <target>。.PHONY寫法也可以讓程式設計師知道哪些工作目標不是針對檔案，增加可讀性。 Make 預設的假工作目標有all, install, clean, distclean, TAGS, info, check。 ``` #### Example 1 ```make clean: rm *.c temp .PHONY:clean //假設同資料夾中有叫做clean的檔案加上.PHONY就可以正常執行clean指令 clean: rm *.c temp ``` #### Example 2 ```make all : prog1 prog2 prog3 .PHONY : all //定義一個all偽目標這個all會去叫prog123 prog1 : prog1.o utils.o //叫做prog的target cc -o prog1 prog1.o utils.o prog2 : prog2.o cc -o prog2 prog2.o prog3 : prog3.o sort.o utils.o cc -o prog3 prog3.o sort.o utils.o ``` ### Variables 1. 宣告時給予初值 2. 使用時在變數名稱前加「$」 ps：最好用小括弧「()」或大括弧「{}」將變數包括起來 3. 使用「$」字元時用「$$」表示 #### Example ``` foo = $(bar) #宣告 foo 的值為 $(bar) , foo=c bar = c #宣告 bar 的值為 c x := foo #宣告 x 的值為 foo y := $(x) bar #宣告 y 的值為 $(x) bar , y=foo bar x := later #宣告 x 的值為 later FOO ?= bar #如前面未定義 FOO 之值將其定義為 bar foo := a.o b.o c.o #宣告foo為 a.o b.o c.o bar := $(foo:.o=.c) #將 foo 中的 .o 全部替換成 .c ``` ### Wildcard - 輸出資料夾中指定格式的文件名稱，以空白分隔 #### Example ```make $(wildcard *) //所有檔案 a b c a.c b.c c.o x.exe $(wildcard *.c) //所有副檔名為c的檔案 a.c b.c $(wildcard c*) //所有檔名為c的檔案 c c.o $(wildcard *.*) //所有有附檔名的檔案 a.c b.c c.o x.exe $(wildcard *.c ./sub/*.c) //同時尋找 ``` --- ## 10/2 stdint.h ### stdint ```c= #include <stdint.h> ``` ``` int8_t :8-bit signed integer int16_t :16-bit signed integer int32_t :32-bit signed integer int64_t :64-bit signed integer uint8_t :8-bit unsigned integer uint16_t :16-bit unsigned integer uint32_t :32-bit unsigned integer uint64_t :64-bit unsigned integer ``` ### Code ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t a = 2; int32_t b = 3; int32_t sum = 0; printf("Please enter the first integer:\n"); scanf( "%d", &a );//不要問為什麼要& L紀說背起來 printf("Please enter the second integer:\n"); scanf("%d", &b ); sum = a + b ; printf("%d + %d = %d\n", a, b, sum ); return 0; } ``` ### Practice Code 【Area of Trapezoid】 ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t b1; int32_t b2; int32_t h; double area; printf("Calculate Area of Trapezoid\n"); printf("Please enter b1 & b2:\n"); scanf( "%d %d", &b1 , &b2 ); printf("Please enter h:\n"); scanf("%d", &h ); area = (float)( b1 + b2 ) * h / 2; printf("Area = %.2f\n",area);//.f設定小數點後第二位 return 0; } ``` ![](https://i.imgur.com/2khyk0m.png) ### 豆知識 ``` 想要在 linux 上離開程式請用 Ctrl + C (Windows 上也可用) 結束輸入使用 Ctrl + Z ``` --- ## 10/4 IF? ### IF ```c= if( condition ) { statements; } ``` #### tips 只有0才不會做if後面的程式 if只會執行底下的一個指令，要執行多個指令要用{}包起來 ### Equality and Relation Operaters | in math | in C | |:-------:|:----:| | < | < | | > | > | | ≤ | <= | | ≥ | >= | | = | == | | ≠ | != | | ∪ | \|\| | | ∩ | && | ## 10/9 Bool and Switch ### 三元運算子 (條件) ？ (若成立則執行) ： (不成立則執行) ### 三元運算子範例 ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t a = 0; int32_t b = 0; printf("Please enter two integers: "); scanf("%d%d", &a, &b); printf( a > b ? "a is greater than b\n" : "a is not greater than b\n"); return 0; } ``` ### Boolean Only two possible values: ture false ### Bool範例 ```c= #include <stdio.h> #include <stdbool.h> int main() { bool a = true; if ( a ) printf( "true\n" ); else printf( "false\n"); return 0; } ``` ### Switch 範例 ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t a = 1; switch( a ) { case 1: printf( "A\n" ); break; case 11: printf( "J\n" ); break; case 12: printf( "Q\n" ); break; case 13: printf( "K\n" ); break; default: printf( "%d\n",a ); }//輸出為A return 0; } ``` ### Practice answer ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t card_number = 0; int32_t suit = 0, num = 0; printf( "Please enter a card number (1-54):" ); scanf( "%d", &card_number ); if( card_number < 1 || card_number > 54 ) { printf( "Wrong Input!\n" ); return 0; } suit = ( card_number - 1 ) / 13; num = ( card_number - 1 ) % 13 + 1; switch( suit ) { case 0: printf( "Spade " ); break; case 1: printf( "Heart "); break; case 2: printf( "Diamond "); break; case 3: printf( "Club "); break; case 4: printf( card_number == 53 ? "BJ\n" : "LJ\n" ); break; default: printf( "Unknown\n" ); break; } if( card_number <= 52) switch( num ) { case 1: printf( "A\n" ); break; case 11: printf( "J\n" ); break; case 12: printf( "Q\n" ); break; case 0: printf( "K\n" ); break; default: printf( "%d\n",num ); break; } return 0; } ``` #### tips bool 的大小為 1 byte bool 可以設為 true false 以外的東西(-127~127) ---  ## 10/16 LOOO...OOOP ### while ```c= while( condition ) { statements; } ``` ### for ```c= for( ; condition ; ) { statements; } ``` ### 豆知識 lower camel case 駝峰命名法 Example:TotalGrade i++ use the current value first ++i use the value after ++ --- ## 10/18 一堆東西要背的Git ### 開始使用 Git 首先開一個資料夾 $ mkdir hello 並進入該資料夾 $ cd hello 建立一個新的 Repository $ git init ### 基本指令 #### status 顯示目前Git的狀態：$ git status #### add 使Git來追蹤我們的檔案：$ git add <檔案> 取消目前追蹤檔案版本：$ git rm --cached #### commit 將此次追蹤的檔案作註解： $ git commit $ git commit -m "輸入此次變更記錄“ 修改當前commit文字： $ git commit --amend #### log 查看commit的歷史紀錄： $ git log $ git log --stat $ git log -p #### branch 從主要 branch 再開出一條新的 branch 來做,這支新開的 branch 會帶著原本 branch 目前狀態, 當完成所要開發的新功能或是 bug 修正後確認沒問題就再把它合併回主 branch 開新 branch： $ git branch <名稱> 列出所有branch： $ git branch #### checkout 切換至其他branch： $ git checkout <名稱> 切換至master branch： $ git checkout master #### push 將檔案傳輸至伺服器： $ git remote add origin <目標伺服器> $ git push –u origin master #### pull 至伺服器中將檔案下載回本機更新： $ git pull --rebase --- ## 10/23 Another Loop ### Do While ```c= do{ statements; }while( condition ); ``` ### 菱形 Author：施衡 ```c= #include <stdio.h> #include <math.h> int main(){ int space = 0, star = 0, N = 0; scanf("%d", &N); for(int i = 0; i < N; i++){ space = abs(i - N / 2); //abs是絕對值 for(int j = 0; j < space; j++) printf(" "); star = N - space * 2; for(int j = 0; j < star; j++) printf("*"); } return 0; } ``` Author：高仔 ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t num=0; printf("Please enter a odd positive number: "); scanf("%d",&num); for(int i = 1 ; i <= num ; i += 2) { for(int j = 0 ; j < (num - i) / 2 ; j++) printf(" "); for(int j = 0 ; j < i ; j++) printf("*"); printf("\n"); } for(int i = num - 2 ; i > 0 ; i -= 2) { for(int j = 0 ; j < (num - i) / 2 ; j++) printf(" "); for(int j = 0 ; j < i ; j++) printf("*"); printf("\n"); } return 0; } ``` --- ## 10/25 Function ### Function Definition ```c= Return_Value_Type Function_Name ( parameter_list ) { Statements; } ``` ### Example ```c= #include <stdio.h> #include <stdint.h> int32_t maximum( int32_t x, int32_t y, int32_t z ); // Function Prototype int main() { int32_t number1 = 0; int32_t number2 = 0; int32_t number3 = 0; printf( "Please enter three integers: " ); scanf( "%d %d %d", &number1, &number2, &number3 ); printf( "Max Value is %d\n", maximum( number1, number2, number3 ) ); return 0; } // Real Function Definition int32_t maximum( int32_t x, int32_t y, int32_t z ) { int32_t max = x; if( y > max ) max = y; if( z > max ) max = z; return max; } ``` ### Practice answer ```c= #include <stdio.h> #include <math.h> double distance(int x1, int y1, int x2, int y2) { return sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2)); } int main() { int a, b, c, d; printf("Please input 4 int number: "); scanf("%d %d %d %d", &a, &b, &c, &d); printf("%lf\n", distance(a, b, c, d)); return 0; } ``` #### tips Never reinventing whe wheel. Search brfore you develop --- ## 10/30 Function Call and Header File ### Function Example ```c= #include <stdio.h> #include <stdint.h> void add_one( int32_t x ); int main() { int32_t number = 10; add_one( number ); printf( "Number is %d\n", number ); //輸出為10 return 0; } void add_one( int32_t x ) { x += 1; //x只存活於此函式中 return; } ``` ### 自己搞標頭檔 #### define(mymax.h) ```c= #ifndef MYMAX_H_INCLUDED #define MYMAX_H_INCLUDED //#pragma once //這行等於1 2 10行的效力，以後只寫這行就好(ANSI C 不支援) #include <stdint.h> int32_t maximum( int32_t x, int32_t y, int32_t z ); // Function Prototype #endif // MYMAX_H_INCLUDED ``` #### definition(mymax.c) ```c= #include "mymax.h" // Real Function Definition int32_t maximum( int32_t x, int32_t y, int32_t z ) { int32_t max = x; if( y > max ) { max = y; } if( z > max ) { max = z; } return max; } ``` #### main(main.c) ```c= // Function example #include <stdio.h> #include <stdint.h> #include "mymax.h" // Main Function int main() { int32_t number1 = 0; int32_t number2 = 0; int32_t number3 = 0; printf( "Please enter three integers: " ); scanf( "%d %d %d", &number1, &number2, &number3 ); printf( "Max Value is %d\n", maximum( number1, number2, number3 ) ); return 0; } ``` #### how to use gcc -c main.c gcc -c mymax.c gcc main.o mymax.o #### Static Link 每個程式都有屬於自己的.o可以用(資本主義) #### Dynamic Link 每個程式共用一個.o(共產主義) ###### tags: [自己找的參考資料](https://blog.gtwang.org/programming/howto-create-library-using-gcc/) --- ## 11/1 Scope and Stattic ### Scope Example ```c= #include <stdio.h> #include <stdlib.h> #include <stdint.h> int32_t x = 1; // Global Variable void get_local_variable( void ); void get_global_variable( void ); int main() { printf( "x = %d\n", x ); //輸出1 int32_t x = 5; // Local Variable printf( "x = %d\n", x ); //輸出5 { int32_t x = 25; // Local Variable printf( "x = %d\n", x ); //輸出25 } get_local_variable(); //輸出100 get_global_variable(); //輸出1 return 0; } void get_local_variable( void ) { int32_t x = 100; // Local Variable printf( "x = %d\n", x ); return; } void get_global_variable( void ) { printf( "x = %d\n", x ); return; } ``` ### Static Example ```c= #include <stdio.h> #include <stdlib.h> #include <stdint.h> void get_static_variable( void ); int main() { for( int32_t i = 0 ; i < 10 ; i++ ) { get_static_variable(); //會印出1到10 } return 0; } void get_static_variable( void ) { static int32_t counter = 0; //雖然依樣一開始就給定記憶體，但是只有在此 //函式中可以使用 counter++; printf( "counter = %d\n" , counter ); return; } ``` --- ## 11/8 L紀開嗆 NO 上課 --- ## 11/13 Recurse & Array ### Example of Recurse ```c= #include <stdio.h> #include <stdint.h> uint64_t power(int32_t x, int32_t y); int main() { int32_t n1 = 0, n2 = 0; printf("Please enter two number: "); scanf("%d%d", &n1, &n2); printf("%d ^ %d = %lu\n", n1, n2, power(n1, n2)); return 0; } uint64_t power(int32_t x, int32_t y) { if(y == 1) return x; return x * power(x, y-1); //呼叫自己 } ``` ### Array Array is a way to store lots of data items of "the same type". #### how to declare an array ```c= array_type array_name[ array_size ]; array_type array_name[ array_size ] = { one_element, one_element ...last_element }; array_type array_name[] = { one_element, one_element ...last_element }; array_type array_name[ array_size ] = { all_same_elements }; ``` #### Example ```c= #include <stdio.h> #include <stdint.h> #include <math.h> int main() { int32_t score[10], sum = 0, average = 0; double ans = 0.0; printf("Please enter 10 stdents score\n"); for(int i = 0 ; i < 10 ; i++) { printf("%d: ", i + 1); scanf("%d",&score[i]); sum += score[i]; } average = sum / 10; sum = 0; for(int i = 0 ; i < 10 ; i++) { sum += (int)pow(score[i] - average, 2); } ans = sqrt(sum / 10); printf("SD of this ten students is %.2lf\n", ans); return 0; } ``` #### tips 陣列是從0開始數 -> int32_t num[20] 的最後一項是 num[19] --- ## 11/20 Define and Sort ### define define is a preporcessor directive, not a C statement. ```c= #include <stdio.h> #include <stdint.h> #define five 5 int main() { int32_t a = five; printf("%d\n", a); //輸出為5 } ``` ### Bubble Sort ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t num[10] = {0}, temp = 0; printf("Please enter 10 numbers: \n"); for(size_t i = 0 ; i < 10 ; i++) scanf("%d", &num[i]); for(size_t i = 0 ; i < 10 ; i++) { for(size_t j = i ; j < 10 ; j++) { if(num[i] > num[j]) { temp = num[j]; num[j] = num[i]; num[i] = temp; } } } for(size_t i = 0 ; i < 10 ; i ++) printf("%d ", num[i]); printf("\n"); return 0; } ``` --- ## 11/22 Passing Array to Function ### Exmaple ```c= #include <stdio.h> #include <stdint.h> void print_array(int32_t b[], size_t size); void print_array_2(int32_t b[6]); int main() { int32_t array[5] = {1, 2, 3, 4, 5}; print_array(array, 5); //輸出為: 1 2 3 4 5 print_array_2(array); //輸出為: 1 2 3 4 5 (某亂數) return 0; } void print_array(int32_t b[], size_t size) { for(size_t i = 0 ; i < size ; i++) printf("%d ", b[i]); printf("\n"); } void print_array_2(int32_t b[6]) { for( size_t i = 0 ; i < 6 ; i++ ) printf( "%d ", b[i] ); printf( "\n" ); } ``` #### tips 將陣列傳至函式裡時，不用設定陣列大小。 --- ## 11/27 2D Array ### Declare 2D array ```c= array_type array_name[ array_row_size ][ array_column_size ] /* int32_t a[2][3]; imagine like: a[0][0] a[0][1] a[0][2] a[0][3] a[1][0] a[1][1] a[1][2] a[1][3] a[2][0] a[2][1] a[2][2] a[2][3] real in memory: a[0][0] a[0][1] a[0][2] a[0][3] a[1][0]... a[2][3] */ ``` #### tips Passing a 2D array into a funtion, you must set bounds except the first: funtion( array[][bounds] ) ### 數字龍捲風 ```c= //不斷向右看走法 //editor: 高仔 #include <stdio.h> #include <stdint.h> int main() { int32_t n = 0, dir = 0; printf("Please enter n(odd): "); scanf("%d", &n); if(!(n % 2)) { printf("Wrong input!\n"); return 0; } printf("\n"); int32_t num[n][n], x = n / 2, y = n / 2; printf("Please fill the %d * %d array(>0): \n", n, n); for(int i = 0 ; i < n ; i++) { for(int j = 0 ; j < n ; j++) { scanf("%d", &num[i][j]); if(num[i][j] <= 0) { printf("Wrong input!\n"); return 0; } } ] printf("\nPlease chose your start direct(1 = up, 2 = right, 3 = down, 4 = left): "); scanf("%d", &dir); if(dir < 0 || dir > 4) { printf("Wrong input!\n"); return 0; } printf("\n"); for(int i = 1 ; i <= n * n ; i++) { if(i % 10 == 1) printf("The %dst number is %d\n", i, num[x][y]); else if(i % 10 == 2) printf("The %dnd number is %d\n", i, num[x][y]); else if(i % 10 == 3) printf("The %drd number is %d\n", i, num[x][y]); else printf("The %dth number is %d\n", i, num[x][y]); num[x][y] = -1; switch(dir) { case 1: x--; if(num[x][y+1] != -1) dir = 2; break; case 2: y++; if(num[x + 1][y] != -1) dir = 3; break; case 3: x++; if(num[x][y - 1] != -1) dir = 4; break; case 4: y--; if(num[x - 1][y] != -1) dir = 1; break; } } printf("\n"); return 0; } ``` --- ## 11/29 Pointer 指標 = 用來儲存記憶體位址的變數 ### Declare a Pointer ```c= int32_t *pointer_name, *another_pointer_name; int32_t * pointer_name; int32_t * pointer_name, i_am_not_a_pointer; ``` ### Example ```c= #include <stdio.h> #include <stdint.h> int main() { int32_t a = 7; printf( "a's value is %d\n", a ); //輸出為7 printf( "a's address is %p\n", &a ); //輸出為a的位址 printf( "\n" ); int32_t *a_ptr = &a; printf( "a_ptr's value is %p\n", a_ptr ); //輸出為a的位址 printf( "a_ptr's address is %p\n", &a_ptr ); //輸出為a_ptr的位址 printf( "The value in %p is %d\n", a_ptr, *a_ptr ); //輸出為a的位址, a的值 return 0; } ``` ###### tips: 可以用print("%p", &a)來印出a的記憶體位址 --- ## 12/4 ->Pointer<- ### Passing Address to Function ```c= #include <stdint.h> #include <stdio.h> #include <math.h> int main() { double score = 60.0; curve( &score ); printf("score now is %g\n", score); //輸出為77.4597 } void curve( double *score ) { *score = sqrt(*score) * 10; return; } ``` #### tips pointer + 1 會相當於 pointer 前進一個元素，如 int32_t *每次就是前進4個 bytes 而用 void *宣告時則是前進1個 byte --- ## 12/11 ### Function Pointer 建立函式指標 ```c= void function(int32_t a);//此為函式 int main(){ void (*func)(int32_t); //void -> (欲指向的函式輸出格式) //(*func) 函式指標的名稱 //(int32_t) 所指函式的輸入值 func = function //指定指標所指位址 } ``` 在函式裡使用函式指標 ```c= bool acmp(int32_t a, int32_t b){ if(a > b) return true; return false; } bool dcmp(int32_t a, int32_t b){ if(a < b) return true; return false; } void bubblesort(int32_t *a, int32_t *e, bool (*cmp)(int32_t a, int32_t b)){ for(int32_t *i = a; i < e; i++){ for(int32_t *j = i; j < e; j++){ if(cmp(*i, *j)){ *i ^= *j; *j ^= *i; *i ^= *j; } } } } ``` ### Memory Management Malloc向電腦要記憶體 ```c= ptr = malloc(bytes);//bytes = 所需要的空間 memset(ptr, content, size)//將ptr ~ ptr+size-1 初始化為content ``` Calloc向電腦要記憶體(自帶初始化為0) ```c= ptr = calloc(elements, size)//elements = 元素數, size = 元素大小 ``` --- ## 12/18 ### Double Pointer pointer of pointer, allocate memory in a function, 2D-array #### Example ```c= #include <stdio.h> #include <stdint.h> #include <stdlib.h> void memory_alloc( int32_t **, size_t ); int main() { size_t size = 0; printf("Please enter an array size: "); scanf( "%lu", &size ); int32_t *ptr = NULL; memory_alloc( &ptr, size ); for( size_t i = 0 ; i < size ; i++ ) { printf( "%4d ", *( ptr + i ) ); if( i % 8 == 7 ) { printf( "\n" ); } } printf("\n"); return 0; } void memory_alloc( int32_t **ptr, size_t s ) { *ptr = calloc( sizeof( int32_t ), s ); // Not 1, why? for( size_t i = 0 ; i < s ; i++ ) { *( *ptr + i ) = i; } return; } ``` ## 12/20 ### char char = int8_t (Ascii code) --- ## Homework Sample code will release after due. ### hw1 **Due: 2019.10.13 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/13zFPYmojN55Cvfxhy6vFlXZDmYFsK17g/preview %} * [Sample code](https://hackmd.io/@NTNUCSIE112/rJqM8z0OH) ### hw2 **Due: 2019.10.20 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/1-9LCXcnFLJDRegsTImdsoCCxqIkyBAVW/preview %} * [Sample code](https://hackmd.io/@NTNUCSIE112/SyEaTYaKr) ### hw3 **Due: 2019.11.03 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/1-9LCXcnFLJDRegsTImdsoCCxqIkyBAVW/preview %} * [Sample code](https://hackmd.io/@NTNUCSIE112/B1aWdHN9H) ### Midterm Exam * Problem {%pdf https://drive.google.com/file/d/11_f_lUthrnPrDIJ7oQKyT9l_ddPKy0ui/preview %} * [Sample code](https://hackmd.io/@joseph89108/ByfFg_ehB) ### hw04 **Due: 2019.12.01 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/1LIQSs2DOVmc2SgMCmM2cy-5lWrCT8SPb/preview %} * [Sample code](https://hackmd.io/@joseph89108/H1gQfLx3S) ### hw05 **Due: 2019.12.15 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/1OsW6WiukyxY4jLmvfDwz8X8LssNlNT6M/preview %} * [Sample code](https://hackmd.io/@joseph89108/rkXQ9m8RS) ### hw06 **Due: 2020.01.05 PM 11:59** * Problem {%pdf https://drive.google.com/file/d/1JpyXOZzqIURI-XZ2Ch8D2uq-AeZz_Fnb/preview %} * [hw06.zip](https://drive.google.com/file/d/125zLpRIVN2OahyqayVGpAkCXLuCyBpJp/view) * [Sample code](https://hackmd.io/@joseph89108/rJepBF_eI) ### Final Exam * Problem {%pdf https://drive.google.com/file/d/1gzrNqLEYqPc5L9xSyVEpdfi0Ed1uz19E/preview %} * [final.zip](https://drive.google.com/file/d/1xio2-krLW4eNnBhy2vxmLApkD1fnEvZm/view) * [Sample code](https://hackmd.io/@joseph89108/SkIELK_x8)  *[iterate]:迴圈 *[recurse]:遞迴

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