算法竞赛入门经典（第二版）3-5谜题UVA277

#include <stdio.h>
#include <string.h>
#define maxn 5
char a[maxn][maxn];
char b[100];
int flag=0;//
int main()
{
    while(1)
    {
        int num=0, blank_x,blank_y;
    while(num<5)
    {
        gets(a[num]);
        num++;
    } 
    printf("test\n");
    int x=0;//int y=0不能在这里定义，原因？？ 
    while(x<5)
    {
        int key=0,y=0;
        while(y<5)
        {   
            if(a[x][y]==' ')
            {
                blank_x=x;
                blank_y=y;
                key=1;
                break;            
            }
            y++;
        }
        if(key==1) {break;}
        x++;
    }
    printf("[%d][%d]--\n",blank_x,blank_y);
    gets(b) ;
    int len = strlen(b);
    char temp;
    for(int i=0;i<len;i++)
    {
        switch(b[i])
        {
            case 'A':  {a[blank_x][blank_y]=a[blank_x-1][blank_y]; 
                       a[blank_x-1][blank_y]=' ';
                       blank_x=blank_x-1;break; 
           }

                       
            case 'B':  {a[blank_x][blank_y]=a[blank_x+1][blank_y]; 
                       a[blank_x+1][blank_y]=' ';
                       blank_x=blank_x+1;break; 
            }
                       
            case 'R':  {a[blank_x][blank_y]=a[blank_x][blank_y+1]; 
                       a[blank_x][blank_y+1]=' ';
                       blank_y=blank_y+1;break; 
            }
                       
            case 'L':  {a[blank_x][blank_y]=a[blank_x][blank_y-1]; 
                       a[blank_x][blank_y-1]=' ';
                       blank_y=blank_y-1;break; 
            }
            case '0': break;           
            default: flag=1;break;                    
        } 
        
    }
    
    if(flag==1) printf("This puzzle has no final configuration.\n");
        else 
        {
            for(int j=0;j<5;j++)
            {
                for(int k=0;k<5;k++)
                {
                    printf(" %c",a[j][k]);
                }
                printf("\n");
            }
        }
     } 
    
}