提示错误在第二个大括号处，经检查，无异常。。。
#include<stdio.h>
main()
{
    int score;
    printf("\nplease enter score(score<=100):");
    scanf("%d",&score);
    if(score==100)
        score=90;
    score=score/10;
    swith(score)
    {
        case 9:
            printf("A");
            break;
        case 8:
            printf("B");
            break;
        case 7:
            printf("C");
            break;
        case 6:
            printf("D");
            break;
        default:
            printf("E");
    }
}