题解 | #走迷宫#

BFS 实现

#include <bits/stdc++.h>

using namespace std;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    vector<vector<int>> movelist{{0,-1},{0,1},{-1,0},{1,0}};
    int n, m;
    cin >> n >> m;
    int sx, sy, tx, ty;
    cin >> sx >> sy >> tx >> ty;
    sx--;
    sy--;
    tx--;
    ty--;
    queue<pair<int, int>> q{};
    int res = 0;
    q.push(make_pair(sx, sy));
    vector<vector<char>> num(n, vector<char>(m, ' '));
    for (int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> num[i][j];
        }
    }
    
    while (!q.empty()) {
        int qlength = q.size();
        for (int i = 0; i < qlength; i++) {
            auto qr = q.front();
            q.pop();
            int x = qr.first;
            int y = qr.second;
            if(x == tx && y == ty) {
                cout << res << endl;
                return 0;
            }
            for (int i = 0; i < 4; i++) {
                int nx = x + movelist[i][0];
                int ny = y + movelist[i][1];
                if(nx >= 0 && nx < n && ny >= 0 && ny < m && num[nx][ny] == '.') {
                    num[nx][ny] = '*';
                    q.push(make_pair(nx, ny));
                }
            }
        }
        res++;
    }
    cout << -1 << endl;
    return 0;
}