#include<stdio.h> int main() { int x; printf("请输入学生成绩\n"); scanf("%d",&x); if(x>100||x<0) printf("score is error."); switch(x/10) { case 9:printf("'A'");break; case 8:printf("'B'");break; case 7:printf("'C'");break; case 6:printf("'D'");break; default:printf("E."); } return 0; }追问