#include <iostream> #include <vector> #include <queue> using namespace std; const int dx[] = {1, -1, 0, 0}; const int dy[] = {0, 0, 1, -1}; bool BFS(int x_s, int y_s, int x_t, int y_t, const vector<string>& grid, vector<vector<int>>& dist) { int n = grid.s...