c语言题目：给出一百分制成绩，要求输出成绩等级‘A'、’B‘、'C'、‘D'、'E’。90分以上为A,80~89分为B，

#include int main() { int score, m; scanf("%d", &score); while (score 100){ printf("Error! Retry!\n"); scanf("%d", &score); } m= score / 10; if (m>= 9) printf("Grade is A!\n"); switch(m){ case 0: pr