1027: 逃离迷宫

到同一个点的同一个方向必须转向次数越来越小

#include <bits/stdc++.h>
using namespace std;
char mp[105][105];
int vis[105][105][4];
int dir[4][2]={{-1,0},{0,1},{1,0},{0,-1}}; //上右下左
struct node{
	int yy;	//图的行坐标 
	int xx;	//图的列坐标 
	int toward;
	int cnt;
};
bool dfs(int k,int yy1,int xx1,int yy2,int xx2){
	stack<node> sta;
	int cnt=0;
	mp[yy1][xx1]='*';
	for(int i=0;i<=3;i++){
		int yy=yy1+dir[i][0];
		int xx=xx1+dir[i][1];
		if(mp[yy][xx]!=0&&mp[yy][xx]!='*'){
			if(cnt+1<vis[yy][xx][i]){
				vis[yy][xx][i]=cnt+1;
			sta.push({yy,xx,i,cnt+1});}
		}
	}
	while(!sta.empty()){
		auto now=sta.top();
		sta.pop();
		//cout<<now.yy<<" "<<now.xx<<" "<<now.toward<<" "<<now.cnt<<" "<<mp[now.yy][now.xx]<<endl;
		if(now.yy==yy2&&now.xx==xx2){
			return true;
		}
		for(int i=0;i<=3;i++){
				int yy=now.yy+dir[i][0];
				int xx=now.xx+dir[i][1];
				if(mp[yy][xx]!=0&&mp[yy][xx]!='*'){
						if(i!=now.toward){
							if(now.cnt<k){
								if(now.cnt+1<vis[yy][xx][i]){
								//cout<<yy<<" "<<xx<<" "<<i<<" "<<now.cnt+1<<endl;
								vis[yy][xx][i]=now.cnt+1;
								sta.push({yy,xx,i,now.cnt+1});
							}}
						}
						else {
							if(now.cnt<vis[yy][xx][i]){
								vis[yy][xx][i]=now.cnt;
								sta.push({yy,xx,i,now.cnt});
							}
						}
					}
				}
			}
	return false;
}
int main(){
	int t; scanf("%d",&t);
	while(t--){
		int m,n;	//m行，n列  
		scanf("%d%d",&m,&n);
		memset(mp,0,sizeof(mp));
		memset(vis,0x3f,sizeof(vis));
		for(int i=1;i<=m;i++){
			scanf("%s",mp[i]+1);
		}
		int k, xx1,yy1,xx2,yy2;
		scanf("%d%d%d%d%d",&k,&xx1,&yy1,&xx2,&yy2);
		if(mp[yy1][xx1]=='*'||mp[yy2][xx2]=='*'){
			printf("no\n");
		}else{
			if(dfs(k+1,yy1,xx1,yy2,xx2)){
				printf("yes\n");
			}
			else 
				printf("no\n");
		}
	}	
	return 0;
}