poj 3894 迷宫问题

Posted 2021-06-15 jpphy0

迷宫问题

http://poj.org/problem?id=3984

代码

// poj 3894 迷宫问题
//#include<bits/stdc++.h>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<queue>
using namespace std;
int dx[4]={1, 0, -1, 0}, dy[4]={0, 1, 0, -1};
int vis[6][6], len[6][6];
struct MZ{int x, y;};
void bfs(){
	queue<MZ> q;
	int x, y;
	q.push({1,1}), vis[1][1] = 1, len[1][1] = 1;
	while(q.size()){
		MZ& tmz = q.front();
		for(int i = 0; i < 4; ++i){
			x = tmz.x+dx[i], y = tmz.y+dy[i];
			if(vis[x][y]) continue;
			if(x > 5 || x < 1 || y > 5 || y < 1) continue;
			vis[x][y] = 1;
			len[x][y] = len[tmz.x][tmz.y]+1;
			q.push({x, y});
		}
		q.pop();
	}
}
void dfs(int x, int y){
	int tx, ty;
	for(int i = 0; i < 4; ++i){
		tx = x+dx[i], ty = y+dy[i];
		if(tx > 5 || tx < 1 || ty > 5 || ty < 1) continue;
		if(len[tx][ty] + 1 == len[x][y]){
			dfs(tx, ty);
			printf("(%d, %d)\\n", x-1, y-1);
			break;
		}
	}
}
int main(){
	memset(vis, 0, sizeof vis);
	memset(len, 0, sizeof len);
    for(int i = 1; i <= 5; ++i)
		for(int j = 1; j <= 5; ++j)
			scanf("%d", &vis[i][j]);
	bfs();
	dfs(5, 5);
    return 0;
}