我用以下的程序AC过了：
#include<stdio.h>
#include<string.h>
int main()
{
    int a,b,t=0,i,j,flag=0;
    int num;
    char mine[200][200];
    scanf("%d%d",&a,&b);
    while(a!=0&&b!=0)
    {
        memset(mine,'.',sizeof(mine));
        for(i=1;i<=a;i++)
        {
            getchar();
            for(j=1;j<=b;j++)
                scanf("%c",&mine[i][j]);
        }
        t++;
        if(flag)printf("\n");
        printf("Field #%d:\n",t);
        for(i=1;i<=a;i++)
        {
            for(j=1;j<=b;j++)
            {
                if(mine[i][j]=='*')putchar('*');
                else
                {
                    int m,n;
                    num=0;
                    for(m=i-1;m<=i+1;m++)
                        for(n=j-1;n<=j+1;n++)
                            if(mine[m][n]=='*')num++;
                    printf("%d",num);
                }
            }
            putchar('\n');
        }
        flag=1;
        scanf("%d%d",&a,&b);
    }
    return 0;
}
那为什么把memeset语句去掉，再把char mine[200][200];改为char mine[200][200]={'\0'};就变成wrong answer了呢？