为什么我的代码样例都过不了，请大佬求助

#include<bits/stdc++.h>
using namespace std;
int n,m,a[105][105],aa[105],ab[105],ta,tb,sa,sb;
void dfs(int x,int y,int z){
	int k=1;
	if(x==sa&&y==sb){
		for(int i=1;i<z;i++){
			cout<<"("<<aa[i]<<","<<ab[i]<<")->";
		}
		cout<<"("<<sa<<","<<sb<<")"<<endl;;
		return;
	}
	if(a[x-1][y]==1){
		aa[z]=x;ab[z]=y;
		dfs(x-1,y,z+1);
		k=0;
	}
	if(a[x][y+1]==1 && k==1){
		aa[z]=x;ab[z]=y;
		dfs(x-1,y,z+1);
		k=0;
	}
	if(a[x-1][y]==1 && k==1){
		aa[z]=x;ab[z]=y;
		dfs(x-1,y,z+1);
		k=0;
	}
	if(a[x-1][y]==1 && k==1){
		aa[z]=x;ab[z]=y;
		dfs(x-1,y,z+1);
		k=0;
	}
}
int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			scanf("%d",&a[i][j]);
		}
	}
	scanf("%d%d%d%d",&ta,&tb,&sa,&sb);
	if(a[ta][tb]==0 || a[sa][sb]==0){
		cout<<"-1";
		return 0;
	}
	dfs(ta,tb,1);
}