class Solution { public: int res = 0; void find(vector<vector<char> >& grid, int i, int j, int m, int n) { int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0}; grid[i][j] = '0'; for(int k = 0; k < 4; k ++) { int x = i + dx[k], y = j + dy[k]; ...