题解

#include <iostream>
#include <vector>
using namespace std;
int n, m, c;
vector<vector<char>> grid;
bool dfs(int i, int j, int steps) {
    if (i < 0 || i >= n || j < 0 || j >= m || grid[i][j] == 'X') {
        return false;
    }
    if (grid[i][j] == 'T' && steps == c) {
        return true;
    }
    if (steps >= c) {
        return false;
    }
    char temp = grid[i][j];
    grid[i][j] = 'X';
    bool found = false;
    found |= dfs(i + 1, j, steps + 1); 
    found |= dfs(i - 1, j, steps + 1); 
    found |= dfs(i, j + 1, steps + 1); 
    found |= dfs(i, j - 1, steps + 1); 
    grid[i][j] = temp;
    return found;
}
int main() {
    int T;
    cin >> T;
    while (T--) {
        cin >> n >> m >> c;
        grid.resize(n, vector<char>(m));
        int start_i, start_j;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cin >> grid[i][j];
                if (grid[i][j] == 'S') {
                    start_i = i;
                    start_j = j;
                }
            }
        }
        if (dfs(start_i, start_j, 0)) {
            cout << "YES" <<"\n";
        } else cout<<"NO"<<"\n";
    }
    return 0;
}