bfs模版

#include <bits/stdc++.h>
using namespace std;
int n, m, sx, sy, tx, ty;
char mp[120][120];

int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};

bool inmap(int x, int y) {
    return x >= 1 && x <= n && y >= 1 && y <= m;
}

int main() {
    cin >> n >> m ;
    queue<pair<int, int>> q;
    vector<vector<int>> dis(n + 1, vector<int> (m + 1, -1));
    
    for (int i = 1;i <= n;i++) 
        for (int j = 1;j <= m;j++) {
            cin >> mp[i][j];
            if (mp[i][j] == 'S') q.push({i, j}), dis[i][j] = 0;
            if (mp[i][j] == 'T') tx = i, ty = j;
        }

    while (!q.empty()) {
        auto t = q.front();
        q.pop();
        int x = t.first;
        int y = t.second;
        if (x == tx && y == ty) break;
        for (int k = 0;k < 4;k++) {
            int nx = x + dx[k];
            int ny = y + dy[k];
            if (!inmap(nx, ny) || dis[nx][ny] != -1 || mp[nx][ny] == '#') continue;
            dis[nx][ny] = dis[x][y] + 1;
            q.push({nx, ny});
        }
    }
    
    cout << dis[tx][ty];
}