bfs不太会，我强行用了dfs

#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,sx,sy,fx,fy;
char ma1[25][25];
int ans[10005];//记录每个到达终点的cnt的值
bool ma2[25][25];//记录是否走过 
int opx[5] = {1,0,0,-1};
int opy[5] = {0,1,-1,0};
int cnt,op=0;//cnt 用于计数 ans 用于记录最小的路径 
void dfs(int x,int y){
	if(x == fx && y == fy){
		ans[op] = cnt;
        op++;
        
	}
	else{
		for(int i = 0; i < 4; i++){
			int nex = x + opx[i];
			int ney = y + opy[i];
			if(nex>=1&&nex<=n&&ney>=1&&ney<=m&&(ma1[nex][ney]=='.'||ma1[nex][ney]=='*')&&!ma2[nex][ney]){
				ma2[nex][ney] = true;
				cnt++; 
				dfs( nex, ney);
				ma2[nex][ney] = false;
                cnt--;
			}
		}
	}
}
int main(){
	std::ios::sync_with_stdio(false);
	cin>>n>>m;
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			cin>> ma1[i][j];
			if(ma1[i][j]=='@')
				sx = i,sy = j;
			if(ma1[i][j]=='*')
				fx = i, fy = j;
		}
	}
	dfs( sx, sy);
    int mini=100005;
    for(int i=0;i<100;i++){
        if(ans[i]&&ans[i]<mini)
            mini=ans[i];
    }
    if(mini != 100005)
	    cout<<mini;
   else
       cout<<-1;
	return 0;
}