如何计算C语言中的ABCDE总数

Question

我正在尝试编写一个C程序，它可以读取学生的分数，直到用户输入文件末尾(EOF)，并确定他们的成绩是A、B、C、D还是E。我在计算A、B、C、D和E的总和时遇到了麻烦。总和总是0(零)。

这就是我尝试过的

#include<stdio.h>

int main()
{

int num_stu, score, counter, total,grade;
int aCount = 0, bCount=0, cCount=0,
    dCount=0, eCount=0;

total = 0;
counter = 1;

printf("Enter how many number of students: ");
scanf("%d",&num_stu);
while (counter <=num_stu){
    printf("Enter student score: ");
    scanf("%d",&score);
if(score>=80)
    printf("Student's grade is A\n");
else
if(score>=70)
    printf("Student's grade is B\n");
else
if(score>=60)
    printf("Student's grade is C\n");
else
if(score>=50)
    printf("Student's grade is D\n");
else
    printf("Student's grade is E\n");

counter=counter+1;
}

while ((grade=getchar()) !=EOF) {

 switch (grade){

 case 'A':case'a':
 ++aCount;
 break;

 case'B': case'b':
 ++bCount;
 break;

 case'C': case'c':
 +cCount;
 break;

 case'D':case'd':
 ++dCount;
 break;

 case'E':case'e':
 ++eCount;
 break;

 case'\n': case' ':
 break;

 default:
 printf("Incorrect letter grade entered.");
 printf("Enter a new grade.\n");
 break;
}
}
printf("\n Totals for each letter grade are: \n");
printf("A: %d\n",aCount);
printf("B: %d\n",bCount);
printf("C: %d\n",cCount);
printf("D: %d\n",dCount);
printf("E: %d\n",eCount);

return 0; }

我是不是做错了什么？提前感谢！

Answer 1

每次按enter键时，都需要删除'\n'。因此，为了消除这些问题，将一个getchar()放在while循环之前，将一个get char放在while循环中。

#include<stdio.h>

int main()
{

    int num_stu, score, counter, total,grade;
    int aCount = 0, bCount=0, cCount=0,
        dCount=0, eCount=0;

    total = 0;
    counter = 1;

    printf("Enter how many number of students: ");
    scanf("%d",&num_stu);
    while (counter <=num_stu){
            printf("Enter student score: ");
            scanf("%d",&score);
        if(score>=80)
            printf("Student's grade is A\n");
        else
        if(score>=70)
            printf("Student's grade is B\n");
        else
        if(score>=60)
            printf("Student's grade is C\n");
        else
        if(score>=50)
            printf("Student's grade is D\n");
        else
            printf("Student's grade is E\n");

        counter=counter+1;
    }

        getchar();
    while ((grade=getchar()) !=EOF) {
        getchar();

        switch (grade){

            case 'A':case'a':
            ++aCount;
            break;

            case'B': case'b':
            ++bCount;
            break;

            case'C': case'c':
            +cCount;
            break;

            case'D':case'd':
            ++dCount;
            break;

            case'E':case'e':
            ++eCount;
            break;

            case'\n': case' ':
            break;

            default:
            printf("Incorrect letter grade entered.");
            printf("Enter a new grade.\n");
            break;
        }
    }
        printf("\nTotals for each letter grade are: \n");
        printf("A: %d\n",aCount);
        printf("B: %d\n",bCount);
        printf("C: %d\n",cCount);
        printf("D: %d\n",dCount);
        printf("E: %d\n",eCount);

    return 0; 
}