11月题单

洗白的迷宫

跳转链接

T167831 洗白的迷宫

要点

深度优先搜索， 记得维护路径！！（不会返回原路）

代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>

using namespace std;

const int N = 60;

typedef pair<int, int> PII;

char map[N][N];
int path[N][N];
int dx[] = { 1, 0, -1, 0 }, dy[] = { 0, 1, 0, -1 }, sx, sy;
queue<PII> q;

int main()
{
	int n;
	cin >> n;

	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
		{
			char c;
			cin >> c;
			if (c == '@') sx = i, sy = j;

			map[i][j] = c;
		}

	memset(path, -1, sizeof(path));
	q.push({ sx, sy });
	path[sx][sy] = 0;

	while(!q.empty())
	{
		int x = q.front().first, y = q.front().second;
		if (map[x][y] == 'E')
		{
			puts("Yes");
			return 0;
		}

		for (int i = 0; i < 4; i++)
		{
			int x = q.front().first + dx[i], y = q.front().second + dy[i];
			if (x >= 0 && x < n && y >= 0 && y < n && map[x][y] != '#' && path[x][y] == -1)
			{
				q.push({ x, y });
				path[x][y] = path[q.front().first][q.front().second];
			}
		}

		q.pop();
	}
	
	puts("No");

	return 0;
}