Untitled

class Solution {
public:
    vector<vector<int>> pacificAtlantic(vector<vector<int>>& heights) {
        vector<vector<int>> result;
        queue<pair<int,int>> BFS;
        queue<pair<int,int>> BFS2;
        bool pacific[250][250] = {false};
        bool atlantic[250][250] = {false};

        for(int i = 0; i < heights.size(); i++) {
            BFS.push(pair<int, int>(i, 0));
            pacific[i][0] = true;
            BFS2.push(pair<int, int>(i, int(heights[i].size()) - 1));
            atlantic[i][int(heights[i].size()) - 1] = true;
        }
        for(int j = 0; j < heights[0].size(); j++) {
            BFS.push(pair<int, int>(0, j));
            pacific[0][j] = true;
            BFS2.push(pair<int, int>(int(heights.size()) - 1, j));
            atlantic[int(heights.size()) - 1][j] = true;
        }
        
        while(!BFS.empty()) {
            pair<int, int> t = BFS.front();
            BFS.pop();
            if(t.first - 1 >= 0 && !pacific[t.first - 1][t.second] && heights[t.first - 1][t.second] >= heights[t.first][t.second]) {
                BFS.push(pair<int,int>(t.first - 1, t.second));
                pacific[t.first - 1][t.second] = true;
            }
            if(t.first + 1 < heights.size() && !pacific[t.first + 1][t.second] && heights[t.first + 1][t.second] >= heights[t.first][t.second]) {
                BFS.push(pair<int,int>(t.first + 1, t.second));
                pacific[t.first + 1][t.second] = true;
            }
            if(t.second - 1 >= 0 && !pacific[t.first][t.second - 1] && heights[t.first][t.second - 1] >= heights[t.first][t.second]) {
                BFS.push(pair<int,int>(t.first, t.second - 1));
                pacific[t.first][t.second - 1] = true;
            }
            if(t.second + 1 < heights[0].size() && !pacific[t.first][t.second + 1] && heights[t.first][t.second + 1] >= heights[t.first][t.second]) {
                BFS.push(pair<int,int>(t.first, t.second + 1));
                pacific[t.first][t.second + 1] = true;
            }
        }

        while(!BFS2.empty()) {
            pair<int, int> t = BFS2.front();
            BFS2.pop();
            if(t.first - 1 >= 0 && !atlantic[t.first - 1][t.second] && heights[t.first - 1][t.second] >= heights[t.first][t.second]) {
                BFS2.push(pair<int,int>(t.first - 1, t.second));
                atlantic[t.first - 1][t.second] = true;
            }
            if(t.first + 1 < heights.size() && !atlantic[t.first + 1][t.second] && heights[t.first + 1][t.second] >= heights[t.first][t.second]) {
                BFS2.push(pair<int,int>(t.first + 1, t.second));
                atlantic[t.first + 1][t.second] = true;
            }
            if(t.second - 1 >= 0 && !atlantic[t.first][t.second - 1] && heights[t.first][t.second - 1] >= heights[t.first][t.second]) {
                BFS2.push(pair<int,int>(t.first, t.second - 1));
                atlantic[t.first][t.second - 1] = true;
            }
            if(t.second + 1 < heights[0].size() && !atlantic[t.first][t.second + 1] && heights[t.first][t.second + 1] >= heights[t.first][t.second]) {
                BFS2.push(pair<int,int>(t.first, t.second + 1));
                atlantic[t.first][t.second + 1] = true;
            }
            
        }
        vector<pair<int, int>> result2;
        for(int i = 0; i < heights.size(); i++)
            for(int j = 0; j < heights[0].size(); j++)
                if(pacific[i][j] && atlantic[i][j])
                    result2.push_back(pair<int,int>(i,j));
        for(int i = 0; i < result2.size(); i++) {
            vector<int> tmp;
            tmp.push_back(result2[i].first);
            tmp.push_back(result2[i].second);
            result.push_back(tmp);
        }
        return result;
    }
};