Question

我正在尝试计算两个骰子每两个骰子滚动的次数百分比。我的“实际”值返回nan，我的预期返回0.我知道代码效率低，我们不允许在这个赋值中使用数组有人可以指出我正确的方向吗？谢谢！

#include <stdio.h>
#include <stdlib.h>
#include <time.h>


int main() {


    int d2 = 0;
    int d3 = 0;
    int d4 = 0;
    int d5 = 0;
    int d6 = 0;
    int d7 = 0;
    int d8 = 0;
    int d9 = 0;
    int d10 = 0;
    int d11 = 0;
    int d12 = 0;


int k, roll_1, roll_2, num_roll, total, count = 0 ;

    float perc, exp;
    srand((long)time(NULL));

    printf("Enter number \n");

    scanf("%d", &num_roll);




for (k = 0; k < num_roll; k++)

            {
            roll_1 = rand() %6 +1;
            roll_2 = rand() %6 +1;
            total = roll_1 + roll_2;
            total++;

            if (total == 2) d2++;
            else if (total == 3) d3++;
            else if (total == 4) d4++;
            else if (total == 5) d5++;
            else if (total == 6) d6++;
            else if (total == 7) d7++;
            else if (total == 8) d8++;
            else if (total == 9) d9++;
            else if (total == 10) d10++;
            else if (total == 11) d11++;
            else if (total == 12) d12++;
     }

printf("Roll\t Total\t Session\tExpected\n\n");


     printf("2:\t %d\t %.3f \t\t %.3f \n", d2, perc, exp);
     printf("3:\t %d\t %.3f \t\t %.3f \n", d3, perc, exp);
     printf("4:\t %d\t %.3f \t\t %.3f \n", d4, perc, exp);
     printf("5:\t %d\t %.3f \t\t %.3f \n", d5, perc, exp);
     printf("6:\t %d\t %.3f \t\t %.3f \n", d6, perc, exp);
     printf("7:\t %d\t %.3f \t\t %.3f \n", d7, perc, exp);
     printf("8:\t %d\t %.3f \t\t %.3f \n", d8, perc, exp);
     printf("9:\t %d\t %.3f \t\t %.3f \n", d9, perc, exp);
     printf("10:\t %d\t %.3f \t\t %.3f \n", d10, perc, exp);
     printf("11:\t %d\t %.3f \t\t %.3f \n", d11, perc, exp);
     printf("12:\t %d\t %.3f \t\t %.3f \n", d2, perc, exp);

  return 0;
  }

Answer 1

total++似乎错了;这是为了什么？
您永远不会向perc或exp分配任何内容。
您打印d2两次，但绝不打印d12。

你应该打开一些警告。对于-Wall，clang说：

example.c:22:41: warning: unused variable 'count' [-Wunused-variable]
int k, roll_1, roll_2, num_roll, total, count = 0 ;
                                        ^
example.c:58:48: warning: variable 'perc' is uninitialized when used here
      [-Wuninitialized]
     printf("2:\t %d\t %.3f \t\t %.3f \n", d2, perc, exp);
                                               ^~~~
example.c:24:15: note: initialize the variable 'perc' to silence this warning
    float perc, exp;
              ^
               = 0.0
example.c:58:54: warning: variable 'exp' is uninitialized when used here
      [-Wuninitialized]
     printf("2:\t %d\t %.3f \t\t %.3f \n", d2, perc, exp);
                                                     ^~~
example.c:24:20: note: initialize the variable 'exp' to silence this warning
    float perc, exp;
                   ^
                    = 0.0
3 warnings generated.

添加-Weverything会产生另一个警告：

example.c:25:11: warning: implicit conversion loses integer precision: 'long' to
      'unsigned int' [-Wshorten-64-to-32]
    srand((long)time(NULL));
    ~~~~~ ^~~~~~~~~~~~~~~~

您可能会或可能不会关心的那个。

纳输出百分比计算，骰子滚动程序

1 个答案: