编辑代码

#include <stdio.h>
int main (void)
{
   int score =0;
    printf("请输入成绩：");
   scanf ("%d",&score);
    if (score <= 100 &&score >=90)
        printf("等级为：A\n");
    else if (score <= 89 &&score >=70)
        printf("等级为：B\n");
    else if (score <= 79 &&score >=60)
        printf("等级为：C\n");
    else 
    printf("不及格\n");
    return 0;
}