``` #include using namespace std; int m, n; vector> sources; vector> targets; int bfs(vector& grid, int removeR, int removeC) { vector> dist(m, vector(n, -1)); queue> q; for(auto [r, c] : sources) { dist[r][c] = 0; q.push({r, c}); } int dr[] = {-1, 1, 0, 0}; int dc[] = {0, 0, -1, 1}; while(!q.empty()) { auto [r, c] = q.front(); q.pop(); for(int k = 0; k < 4; k++) { int nr = r + dr[k]; int nc = c + dc[k]; if(nr < 0 || nr >= m || nc < 0 || nc >= n) continue; if(dist[nr][nc] != -1) continue; if(grid[nr][nc] == 'B' && !(nr == removeR && nc == removeC)) continue; dist[nr][nc] = dist[r][c] + 1; q.push({nr, nc}); } } int maxTime = 0; for(auto [r, c] : targets) { if(dist[r][c] == -1) return INT_MAX; maxTime = max(maxTime, dist[r][c]); } return maxTime; } vector solve(vector& grid) { m = grid.size(); n = grid[0].size(); vector> blockers; for(int i = 0; i < m; i++) { for(int j = 0; j < n; j++) { if(grid[i][j] == 'S') sources.push_back({i, j}); else if(grid[i][j] == 'T') targets.push_back({i, j}); else if(grid[i][j] == 'B') blockers.push_back({i, j}); } } if(targets.empty()) return {0, -1, -1}; if(sources.empty()) return {-1, -1, -1}; int bestTime = bfs(grid, -1, -1); int bestR = -1; int bestC = -1; for(auto [r, c] : blockers) { int time = bfs(grid, r, c); if(time < bestTime) { bestTime = time; bestR = r; bestC = c; } } if(bestTime == INT_MAX) return {-1, -1, -1}; return {bestTime, bestR, bestC}; } int main() { vector grid = { "SBT" }; vector ans = solve(grid); cout << ans[0] << " " << ans[1] << " " << ans[2] << endl; return 0; } ```

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