92分求条

#include<bits/stdc++.h>
using namespace std;
//#define int long long
int _x[]={0,1,0,-1,0},_y[]={0,0,1,0,-1};
bool ne[305][305],v[305][305];
int a[305][305];
int m;
struct N{
	int x,y,k;
};
queue<N> q;
struct M{
	int x,y,t;
}b[50005];
int tot=1;
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
//  cout.tie(0);
	cin>>m;
	memset(a,127,sizeof(a));
	for(int i=1;i<=m;i++){
		int x,y,t;
		cin>>x>>y>>t;
		b[i].x=x,b[i].y=y,b[i].t=t;
		for(int j=0;j<=4;j++){
			if(x+_x[j]>=0&&y+_y[j]>=0) ne[x+_x[j]][y+_y[j]]=1,a[x+_x[j]][y+_y[j]]=min(a[x+_x[j]][y+_y[j]],t);
		}
	}
	v[0][0]=1;
	q.push((N){0,0,0});
	while(q.size()){
		N tmp=q.front();
		q.pop();
		int x=tmp.x,y=tmp.y,k=tmp.k;
//		cout<<x<<" "<<y<<" "<<k<<endl;
		if(!ne[x][y]){
			cout<<k;
			return 0;
		}
		for(int i=1;i<=4;i++){
			int rx=x+_x[i],ry=y+_y[i];
			if(!(rx<0||rx>300||ry<0||ry>300||a[rx][ry]<=k+1||v[rx][ry])){
//					cout<<"||"<<rx<<" "<<ry<<" "<<k+1<<endl;
				v[rx][ry]=1;
				q.push((N){rx,ry,k+1});
			}
		}
	}
	cout<<"-1";
	return 0;
}/*
//..
///.
///.
./..
////
////
///.
./..
*/