题解 | 迷宫寻路

#include <bits/stdc++.h>
using namespace std;
char a[110][110]; 
int n, m;
bool vis[110][110];
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
bool found = false; // 标记是否找到路径

void dfs(int x, int y) {
    if (x == n && y == m) { // 到达终点
        found = true;
        return;
    }
    for (int i = 0; i < 4; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (nx < 1 || nx > n || ny < 1 || ny > m) continue;
        if (a[nx][ny] == '#') continue;
        if (!vis[nx][ny]) {
            vis[nx][ny] = 1;
            dfs(nx, ny);
            if (found) return; // 找到路径后提前退出
        }
    }
}

int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
        }
    }
    vis[1][1] = 1;
    dfs(1, 1);
    cout << (found ? "Yes" : "No") << endl;
    return 0;
}