啊哈算法-解救小哈

#include<stdio.h>
int a[1005][1005],n,m,n_x,n_y,s_x,s_y,book[1005][1005],min=1005;
void find(int x,int y,int step);
void go(int x,int y);
int main(){
    scanf("%d%d",&n,&m);
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++) scanf("%d",&a[i][j]);//画地图
    }
    scanf("%d%d%d%d",&s_x,&s_y,&n_x,&n_y);
    find(s_x,s_y,0);//我这里定义的地图边界是0，书上是1，所以初始位置和找的点的位置要-1； 
    printf("%d",min); 
    return 0;
}
void find(int x,int y,int step){
    if(x==n_x && y==n_y){
        if(min>step) min=step;
        return ; 
    }
    if(x-1>=0 && a[x-1][y]==0 && book[x-1][y]==0){ 
        book[x-1][y]=1;
        find(x-1,y,step+1);
        book[x-1][y]=0;
    }
    if(x+1<=n-1  && a[x+1][y]==0 && book[x+1][y]==0){ 
        book[x+1][y]=1;
        find(x+1,y,step+1);
        book[x+1][y]=0;
    }
    if(y-1>=0 && a[x][y-1]==0 && book[x][y-1]==0){ 
        book[x][y-1]=1;
        find(x,y-1,step+1);
        book[x][y-1]=0;
    }
    if(y+1<=m-1  && a[x][y+1]==0 && book[x][y+1]==0){ 
        book[x][y+1]=1;
        find(x,y+1,step+1);
        book[x][y+1]=0;
    }
    return ;
}
/*
测试样例 
5 4
0 0 1 0
0 0 0 0
0 0 1 0
0 1 0 0
0 0 0 1
0 0 3 2
输出：7 
*/

debug了半天最后发现是初始的地图和书上画的不一样的边界= =