在C

Question

我是编程的新手，我正在尝试完成一项编程练习，在该练习中，老师（用户）将输入成绩，并不断提示他们输入成绩，直到他们输入“ -1”为止。输入后，提示将结束，并且应该输出所有用户输入的成绩的平均值，以及输入的最高和最低成绩。

这是我到目前为止的代码。

#include <stdio.h>

int main()
{
    unsigned int counter;
   float average;
    int grade, total, max, min;

    total=0;
   counter=0;
   max=100;
   min=0;

   printf("Please enter grades, enter -1 to stop\n");
   scanf ("%d", &grade);
   max=min=grade;

   while ( grade !=-1 ) {
       total = total+ grade;
       counter= counter +1;
       if (grade > max)
       max = grade;
       if (grade < min)
       min = grade;
       printf("Please enter grades, enter -1 to stop\n");
   scanf ("%d", &grade);
   max=min=grade;
   }

if ( counter !=0 ) {
    average = (float) total / counter;
    printf("Your average is %.2f\n",average);
    printf("Your highest grade is %d\n", max);
    printf("Your lowest grade is %d\n", min);
}
  else {
      printf("No grades were entered\n");
  }

}

以下是示例代码的输入结果：

Please enter grade, enter -1 to stop                                                                            
95                                                                                                              
Please enter grade, enter -1 to stop                                                                            
87                                                                                                              
Please enter grade, enter -1 to stop                                                                            
-1                                                                                                              
Your average is 91.00                                                                                           
Your highest grade is -1                                                                                        
Your lowest grade is -1    

我不知道为什么它不能显示正确的值，在这种情况下，最高为95，最低为87。我将不胜感激，因为它是我需要解决的程序的唯一部分。

谢谢。

Answer 1

在while循环中，您第二次在程序中提到 min = max = grade 。 那就是从用于停止程序的等级取-1的值。 请注释该行并尝试使用。

Answer 2

这里：

   #include <stdio.h>

int main()
{
    unsigned int counter;
   float average;
    int grade, total, max, min;

    total=0;
   counter=0;
   max=100;
   min=0;

   printf("Please enter grades, enter -1 to stop\n");
   scanf ("%d", &grade);
   max=min=grade;

   while ( grade !=-1 ) 
  {
       total = total+ grade;
       counter= counter +1;
       if (grade > max)
        {
         max = grade;
        }
       if (grade < min)
        {
         min = grade;
        }
       printf("Please enter grades, enter -1 to stop\n");
   scanf ("%d", &grade);

   }

if ( counter !=0 ) 
{
    average = (float) total / counter;
    printf("Your average is %.2f\n",average);
    printf("Your highest grade is %d\n", max);
    printf("Your lowest grade is %d\n", min);
}

  else 
{
      printf("No grades were entered\n");
  }