{"nbformat":4,"nbformat_minor":0,"metadata":{"colab":{"name":"Week04.ipynb","provenance":[],"authorship_tag":"ABX9TyPjngAClNn/AfDSOvOxrZhI"},"kernelspec":{"name":"python3","display_name":"Python 3"},"language_info":{"name":"python"}},"cells":[{"cell_type":"markdown","source":["# 第四週上課內容"],"metadata":{"id":"9xoK4OIjIfZA"}},{"cell_type":"markdown","source":["###GitHub 教材參考資料\n","\n","1. 型別轉換 \n","2. for loop 以及雙層 for loop\n","3. 條件判斷 `if else`   `&&` 與 `||` 與 `!`\n","4. 迴圈和條件判斷搭配\n","\n","\n","\n","https://github.com/htchen/i2p-nthu/tree/master/程式設計一/Operators%2C%20Expressions%2C%20and%20Statements\n","\n","https://github.com/htchen/i2p-nthu/tree/master/程式設計一/Looping\n","\n","https://github.com/htchen/i2p-nthu/blob/master/程式設計一/if%20else/if%20else.md\n"],"metadata":{"id":"05G1Fqg6GRZX"}},{"cell_type":"markdown","source":["##Example 1\n","\n","```\n","for loop\n","for (initialize; test; update) {\n","  ...\n","}\n","```\n","\n","```\n","for ( 初始化 initialize ; 是否繼續執行的條件判斷 test ; 更新變數值 update ) { \n","  ...\n","\n","}\n","```\n","\n","其中三個區域的每個區域所做的事情還可稍加變化。如果什麼都沒有，寫成\n","```\n","for ( ; ; ) {\n","  printf(\"Do something.\\n\");\n","}\n","```\n","作用則相當於無窮迴圈。\n","\n","\n","---\n","\n","其他 Assignment 符號: `+=，-=，*=，/=，%=`\n","\n","這些可看成是簡寫的 assignment 符號，`x += 5;`相當於 `x = x + 5;` 而 `y %= 7;` 相當於 `y = y % 7;` 以此類推。 \n","\n","在 `for` 迴圈的第三部份 (更新變數值) 用這樣的寫法會比較簡潔，但你不一定要用這樣的寫法，\n","\n","只要順著自己的習慣 就可以。知道有這樣的寫法，看到別人的程式用到這種寫法才能知道它的意思。\n","\n","在 `for` 迴圈的第一部份 (初始化) 和第三部份 (更新變數值)，其實允許我們做兩個以上的 statements。"],"metadata":{"id":"Tgxixt6ywNp1"}},{"cell_type":"code","source":["%%writefile E04_01.c\n","#include <stdio.h>\n","int main(void)\n","{\n","\tchar ch;\n","\tfor (ch = 'a'; ch <= 'z'; ch++) {\n","\t\tprintf(\"The ASCII value for %c is %d.\\n\", ch, ch);\n","\t}\n","\treturn 0; \n","}"],"metadata":{"id":"gQGtjE5xwgOd","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646742375148,"user_tz":-480,"elapsed":13,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"a98254a0-cf58-4266-f763-9194c89b2763"},"execution_count":1,"outputs":[{"output_type":"stream","name":"stdout","text":["Writing E04_01.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_01.c -o E04_01\n","./E04_01"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"uywwODIEWzPt","executionInfo":{"status":"ok","timestamp":1646742400018,"user_tz":-480,"elapsed":833,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"0bbe5ec7-c3f1-4a36-bf1a-aa7a0a3271a9"},"execution_count":2,"outputs":[{"output_type":"stream","name":"stdout","text":["The ASCII value for a is 97.\n","The ASCII value for b is 98.\n","The ASCII value for c is 99.\n","The ASCII value for d is 100.\n","The ASCII value for e is 101.\n","The ASCII value for f is 102.\n","The ASCII value for g is 103.\n","The ASCII value for h is 104.\n","The ASCII value for i is 105.\n","The ASCII value for j is 106.\n","The ASCII value for k is 107.\n","The ASCII value for l is 108.\n","The ASCII value for m is 109.\n","The ASCII value for n is 110.\n","The ASCII value for o is 111.\n","The ASCII value for p is 112.\n","The ASCII value for q is 113.\n","The ASCII value for r is 114.\n","The ASCII value for s is 115.\n","The ASCII value for t is 116.\n","The ASCII value for u is 117.\n","The ASCII value for v is 118.\n","The ASCII value for w is 119.\n","The ASCII value for x is 120.\n","The ASCII value for y is 121.\n","The ASCII value for z is 122.\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":2}]},{"cell_type":"markdown","source":["##Example 2\n","for loop 多做幾件事\n","\n","`for (n=1, cost=FIRST_PACK; n<=10; n++, cost+=NEXT_PACK)`"],"metadata":{"id":"zNUTiLmOYNeW"}},{"cell_type":"code","source":["%%writefile E04_02.c\n","#include <stdio.h>\n","#define FIRST_PACK 7\n","#define NEXT_PACK 5\n","int main(void)\n","{\n","\tint n, cost;\n","\tprintf(\" packs costs\\n\");\n","\tfor (n=1, cost=FIRST_PACK; n<=10; n++, cost+=NEXT_PACK) {\n","\t\tprintf(\"%5d     $%-5d\\n\", n, cost);\n","\t}\n","\treturn 0; \n","}"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"TQmPcAFzXOgo","executionInfo":{"status":"ok","timestamp":1646742505622,"user_tz":-480,"elapsed":310,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"3a771b18-1568-4257-9daa-81f9c13c5bb7"},"execution_count":3,"outputs":[{"output_type":"stream","name":"stdout","text":["Writing E04_02.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_02.c -o E04_02\n","./E04_02"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"1idm33scXTOr","executionInfo":{"status":"ok","timestamp":1646742520746,"user_tz":-480,"elapsed":270,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"0718d77b-6dcb-4a51-ce11-7842a7547692"},"execution_count":4,"outputs":[{"output_type":"stream","name":"stdout","text":[" packs costs\n","    1     $7    \n","    2     $12   \n","    3     $17   \n","    4     $22   \n","    5     $27   \n","    6     $32   \n","    7     $37   \n","    8     $42   \n","    9     $47   \n","   10     $52   \n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":4}]},{"cell_type":"markdown","source":["##Exercise 1\n","```\n","/* \n","使用者輸入想要顯示的長方形的高度和寬度\n","輸出一個由 * 構成且符合使用者輸入之大小的長方形\n","可以使用額外的變數 k\n","也可以只用到 i 和 j (利用 % 符號做求餘數的運算)\n","把下面程式碼 ??? 填入正確的運算式\n","讓程式可以達到預期的效果\n","*/\n","#include <stdio.h>\n","int main(void)\n","{\n","    int i, j, k; \n","    scanf(\"%d%d\", &i, &j); \n","    for(???; ???; ???) { \n","        for (???; ???; ???) { \n","            printf(\"*\");\n","        }\n","        printf(\"\\n\");\n","    }      \n","\n","    return 0;\n","}\n","```"],"metadata":{"id":"1I4GTrr-Xf-X"}},{"cell_type":"code","source":["%%writefile W04_01.c\n","/* \n","使用者輸入想要顯示的長方形的高度和寬度\n","輸出一個由 * 構成且符合使用者輸入之大小的長方形\n","可以使用額外的變數 k\n","也可以只用到 i 和 j (利用 % 符號做求餘數的運算)\n","把下面程式碼 ??? 填入正確的運算式\n","讓程式可以達到預期的效果\n","*/\n","#include <stdio.h>\n","int main(void)\n","{\n","    int i, j, k; \n","    scanf(\"%d%d\", &i, &j); \n","    for(; i>0; --i) { \n","        for (k=j; k>0; --k) { \n","            printf(\"*\");\n","        }\n","        printf(\"\\n\");\n","    }      \n","\n","    return 0;\n","}"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"pwDEwV2KXpZ-","executionInfo":{"status":"ok","timestamp":1646742808715,"user_tz":-480,"elapsed":303,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"646c53a2-0de8-47b4-fbc6-0f07ce050336"},"execution_count":9,"outputs":[{"output_type":"stream","name":"stdout","text":["Overwriting W04_01.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc W04_01.c -o W04_01\n","./W04_01\n"],"metadata":{"id":"T2IZO6YmXzoM","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646742821966,"user_tz":-480,"elapsed":3720,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"31dfb11d-0f0f-41e4-d0f4-f8a5c0730440"},"execution_count":10,"outputs":[{"output_type":"stream","name":"stdout","text":["5 7\n","*******\n","*******\n","*******\n","*******\n","*******\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":10}]},{"cell_type":"markdown","source":["##Example 3\n","\n","雙層迴圈"],"metadata":{"id":"JpsLGZK4YGx9"}},{"cell_type":"code","source":["%%writefile E04_03.c\n","#include <stdio.h>\n","// global array\n","int b[1000000][1000000];\n","int f(void)\n","{\n","    b[0][1] = 3;\n","    return b[1][0];\n","}\n","int main(void)\n","{\n","    int i, j;\n","\n","    printf(\"Go!\\n\");\n","    for (i = 0; i < 1000000; i++) {\n","        for (j = 0; j < 1000000; j++) {\n","            b[i][j] = i*j;\n","        }\n","    }\n","    printf(\"Done.\\n\");\n","\n","    for (i = 1; i <= 9; i++) {\n","        for (j = 1; j <= 9; j++) {\n","            printf(\"%3d\", b[i][j]);\n","        }\n","        printf(\"\\n\");\n","    }\n","\n","    return 0;\n","}"],"metadata":{"id":"rHlzKwUaYB_t"},"execution_count":null,"outputs":[]},{"cell_type":"code","source":["%%shell\n","gcc E04_03.c -o E04_03"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"wMY92o71YuyE","executionInfo":{"status":"ok","timestamp":1646743164809,"user_tz":-480,"elapsed":284,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"a8bed6ca-aaed-43a8-fd45-991454250ad7"},"execution_count":27,"outputs":[{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":27}]},{"cell_type":"code","source":["%%time\n","!./E04_03"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"dbe2k6B3ZkQq","executionInfo":{"status":"ok","timestamp":1646743456543,"user_tz":-480,"elapsed":14756,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"56bb91d5-6874-4e41-84b7-5314d6360d1c"},"execution_count":29,"outputs":[{"output_type":"stream","name":"stdout","text":["Go!\n","^C\n","CPU times: user 109 ms, sys: 38.3 ms, total: 147 ms\n","Wall time: 14.5 s\n"]}]},{"cell_type":"code","source":["%%writefile test.c\n","#include <stdio.h>\n","#include <string.h>\n","unsigned long my_strlen(char s[])\n","{\n","    unsigned long i = 0;\n","    while (s[i++]);\n","    return i-1;\n","}\n","int main(void)\n","{\n","    char str[10];\n","    str[0] = 65;\n","    str[1] = 80;\n","    str[2] = 80;\n","    str[3] = EOF;\n","    str[4] = 0;\n","    printf(\"%s %lu\\n\", str, my_strlen(str));\n","    return 0;\n","}\n"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"D8VW2F1FkBDw","executionInfo":{"status":"ok","timestamp":1646743988819,"user_tz":-480,"elapsed":272,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"12700e2b-5490-4fb1-ba71-18f635a902ed"},"execution_count":44,"outputs":[{"output_type":"stream","name":"stdout","text":["Overwriting test.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc test.c -o test\n","./test"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"SZUIGyjCke5x","executionInfo":{"status":"ok","timestamp":1646743994059,"user_tz":-480,"elapsed":508,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"3abddca9-39a1-4376-9433-7c4a8fbba400"},"execution_count":45,"outputs":[{"output_type":"stream","name":"stdout","text":["APP� 4\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":45}]},{"cell_type":"markdown","source":["##Example 4\n","\n","使用 `getchar()` 和 `putchar()`"],"metadata":{"id":"tSPYrAKcZy0v"}},{"cell_type":"code","source":["%%writefile E04_04.c\n","/* \n","使用者輸入一串字元(讀到 '\\n' 就結束)\n","把這串字元裡全部的英文字母都轉成大寫再輸出 \n","*/\n","#include <stdio.h>\n","#include <ctype.h>\n","int main(void)\n","{\n","   char ch;\n","\n","   while ( (ch=getchar()) != '\\n' ) {         \n","      putchar(tolower(ch));\n","   }\n","\n","   putchar('\\n');   \n","\n","   return 0;\n","}"],"metadata":{"id":"_6ZnxeRPZ6iP","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646744199351,"user_tz":-480,"elapsed":265,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"ad79233e-2815-4d2a-9570-75dee93f69c7"},"execution_count":50,"outputs":[{"output_type":"stream","name":"stdout","text":["Overwriting E04_04.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_04.c -o E04_04\n","./E04_04"],"metadata":{"id":"qGfIGnq7aExf","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646744212076,"user_tz":-480,"elapsed":9381,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"1d154dfa-56f2-4b77-e9f1-802929801cc8"},"execution_count":51,"outputs":[{"output_type":"stream","name":"stdout","text":["aBcDe\n","abcde\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":51}]},{"cell_type":"markdown","source":["##Example 5\n","\n","`if` (條件判斷) {\n","}\n","列出因數\n"],"metadata":{"id":"QYQvlILjaMgi"}},{"cell_type":"code","source":["%%writefile E04_05.c\n","/*\n","輸入一個正整數\n","程式必須列出除了 1 和該正整數本身以外的全部因數\n","因數必須從小到大排列\n","如果無法因數分解\n","則成是必須顯示這個正整數是質數\n","*/\n","#include <stdio.h>\n","int main(void)\n","{\n","   int num, div;\n","   int isPrime = 1;\n","\n","   printf(\"Please enter an integer (q to quit): \\n\");\n","\n","   scanf(\"%d\", &num);\n","   for (div=2; div*div <= num ; div++ ) {\n","       if (num%div == 0) {\n","         printf(\"%d, \", div); \n","         isPrime = 0;        \n","       }\n","   }\n","   for (div-=2; div > 1; div--) {\n","       if (num%div == 0) {\n","         printf(\"%d, \", num/div);         \n","       }\n","   }\n","\n","   if (isPrime == 1) {\n","      printf(\"%d is prime.\\n\", num);\n","   } else {\n","      printf(\" are divisors of %d\\n\", num);\n","   }\n","   return 0;\n","}"],"metadata":{"id":"Kg8LMdcYaX9I","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646745287868,"user_tz":-480,"elapsed":277,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"1044f8a6-3def-4bd8-8e1c-b82bbb676657"},"execution_count":76,"outputs":[{"output_type":"stream","name":"stdout","text":["Overwriting E04_05.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_05.c -o E04_05\n","./E04_05"],"metadata":{"id":"SL1x7X9gaiiO","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646745348368,"user_tz":-480,"elapsed":8036,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"42d90a2d-837a-4065-f919-ec691ff74e5f"},"execution_count":82,"outputs":[{"output_type":"stream","name":"stdout","text":["Please enter an integer (q to quit): \n","9\n","3,  are divisors of 9\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":82}]},{"cell_type":"markdown","source":["##Example 6\n","\n","`if` expression"],"metadata":{"id":"pSimQM-8aqt6"}},{"cell_type":"code","source":["%%writefile E04_06.c\n","/*\n","定義一個 function (取名為 check)\n","檢驗下面的 expression \n","根據 expression 的值\n","輸出對應的資訊 \"True\" 或 \"False\"\n","*/\n","#include <stdio.h>\n","void check(int cond)\n","{\n","    if (cond) {\n","        printf(\"True\\n\");\n","    } else {\n","        printf(\"False\\n\");\n","    } \n","}\n","int main(void)\n","{\n","   int x = 5; \n","   int y = 3;\n","   \n","   check(x > 2 && y == 3);\n","   check( !(x < 2 || y == 3) );\n","   check(x != 0 && y);\n","   check(x == 0 || !y);\n","   check(x != y && (20/x) < y);\n","   check( !(y>5 || y<2) && !(x%5) );\n","   check(!x && x);\n","       \n","   return 0;\n","}"],"metadata":{"id":"Mqsrrc2YalHD","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646745785049,"user_tz":-480,"elapsed":294,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"f23e7894-2850-42bc-fcca-3697a086fbb9"},"execution_count":83,"outputs":[{"output_type":"stream","name":"stdout","text":["Writing E04_06.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_06.c -o E04_06\n","./E04_06"],"metadata":{"id":"GUvRctw8a1Mx","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1646745790094,"user_tz":-480,"elapsed":284,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"cd03e2d1-f485-4541-c7a4-3baaf37c460e"},"execution_count":84,"outputs":[{"output_type":"stream","name":"stdout","text":["True\n","False\n","True\n","False\n","False\n","True\n","False\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":84}]},{"cell_type":"markdown","source":["##Example 7\n","找出滿足餘數條件的最小正數"],"metadata":{"id":"jUvTa6IsbHE0"}},{"cell_type":"code","source":["%%writefile E04_07.c\n","/*\n","Find the smallest N that satisfies\n","    N % x == a\n","    N % y == b\n","    N % z == c\n","For example,\n","if x=3, y=5, z=7, and a=2, b=3, c=4,\n","then, N is 53 since\n","    53 % 3 == 2\n","    53 % 5 == 3\n","    53 % 7 == 4\n","and 53<=3*5*7.\n","\n","Another test case:\n","Input:\n","23 29 37\n","10 20 30\n","Output:\n","14201\n"," */\n","#include <stdio.h>\n","int main(void)\n","{\n","    int x, y, z;\n","    int a, b, c;\n","    int i;\n","    scanf(\"%d%d%d\", &x, &y, &z);\n","    scanf(\"%d%d%d\", &a, &b, &c);\n","    for (i=1; i<=x*y*z*5; i++) {\n","          if (i%x==a && i%y==b && i%z==c) {\n","            printf(\"%d\\n\", i);\n","            break;\n","          }\n","    }\n","    return 0;\n","}"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"zzerIzxQbDDy","executionInfo":{"status":"ok","timestamp":1646746080500,"user_tz":-480,"elapsed":283,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"116b6f40-23d6-4b30-ca9f-063066c4a1d8"},"execution_count":87,"outputs":[{"output_type":"stream","name":"stdout","text":["Overwriting E04_07.c\n"]}]},{"cell_type":"code","source":["%%shell\n","gcc E04_07.c -o E04_07\n","./E04_07"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"I5DNPoyJbdxQ","executionInfo":{"status":"ok","timestamp":1646746092029,"user_tz":-480,"elapsed":9103,"user":{"displayName":"HT Chen","photoUrl":"https://lh3.googleusercontent.com/a/default-user=s64","userId":"17748361917871513601"}},"outputId":"b8e86fbd-97b4-47f5-911c-e3d464127c6f"},"execution_count":88,"outputs":[{"output_type":"stream","name":"stdout","text":["3 5 7\n","2 3 4\n","53\n","158\n","263\n","368\n","473\n"]},{"output_type":"execute_result","data":{"text/plain":[""]},"metadata":{},"execution_count":88}]},{"cell_type":"markdown","source":["##Example 8\n","\n","程式碼測試階段，可以在 `main` 一開始的地方加入底下的程式碼，這樣每次執行時就不必手動重複輸入測試資料：\n","\n","```\n","    freopen(\"testcase.txt\", \"r\", stdin);\n","    freopen(\"output.txt\", \"w\", stdout);\n","```\n","\n","`testcase.txt` 是你自己編輯的測試資料文字檔\n","\n","`output.txt` 則會由程式自動產生，檔案裡面會是程式執行的結果\n","\n","最後上傳到 Online Judge 的程式碼記得要用 `/*` `*/` 把上面兩行變成註解"],"metadata":{"id":"dHQBaha-cAUQ"}}]}