DFS解决最短路径问题

#include<stdio.h>
#include<string.h>
#define MAX 100
int vis[MAX][MAX]={0}, map[MAX][MAX];//其中的1表示墙壁，0表示可以走的路
int min = 10000;
int n = 0;
void dfs(int depth, int x, int y)//x代表行，y代表列
{
    if(x >= n || x < 0 || y >= n || y < 0)  return;
    if(vis[x][y] == 1 || map[x][y] == 1)  return;
    if(x == y && y==4) {
        if(min > depth)
          min = depth;
          return;
    }
    vis[x][y] == 1;
                dfs(depth+1,x-1,y);
    dfs(depth+1,x,y-1);     dfs(depth+1,x,y+1);
                dfs(depth+1,x+1,y);
    vis[x][y] == 0;
}
int main()
{
    scanf("%d", &n);
    memset(map,0,sizeof(map));
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            {
                scanf("%d",&map[i][j]);
                vis[i][j] = map[i][j];
            }
            dfs(0,0,0);
    if(min == 10000)
      printf("No\n");
     else
      printf("%d\n",min);
        
    return 0;

 }