【暑期基础】E HDU 2004 成绩转换

（0）考虑分数不合法的qingkuang

（1）分数合法则可用 switch 分类

#include <stdio.h>int main() {int val;while( scanf("%d", &val) != EOF ) {    if( val < 0 || val > 100) {        printf("Score is error!\n");        continue;    }    switch ( val / 10 ) {        case 10:        case 9: printf("A\n"); break;        case 8: printf("B\n"); break;        case 7: printf("C\n"); break;        case 6: printf("D\n"); break;        case 5:        case 4:        case 3:        case 2:        case 1:        case 0: printf("E\n"); break;        default : break;    }}return 0;}