#include<stdio.h>
int main()
{
int A=0, B=0, C=0, D=0, E=0, grade, x=1;
printf("请输入百分制成绩:\n");
while (x > 0)
{
scanf_s("%d", &x);
if (x <= 100)
{
grade = x / 10;
switch (grade)
{
case 10:
A++;
break;
case 9:
A++;
break;
case 8:
B++;
break;
case 7:
C++;
break;
case 6:
D++;
break;
default:
E++;
}
}
}
printf("各分数段人数为:\n90-100:%d\n80-89:%d\n70-79:%d\n60-69:%d\n0-59:%d\n", A, B, C, D, E);
输入的x大于100后,if内部的switch依旧会执行default,使E++。