Vertical Order Traversal of a Binary Tree

 https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree/

https://gist.github.com/SuryaPratapK/d73b9a97c2c8a2af762af106b794ad2d      //soln

class Solution {

map<int,map<int,multiset<int>>> mymap;

void solve(TreeNode *curr,int col,int row)

{

if(!curr)

return;

mymap[col][row].insert(curr->val);

solve(curr->left,col-1,row+1);

solve(curr->right,col+1,row+1);

}

public:

vector<vector<int>> verticalTraversal(TreeNode* root) {

solve(root,0,0);

vector<vector<int>> ans;

for(auto m1: mymap)

{

ans.push_back(vector<int>());

for(auto m2: m1.second)

{

for(auto m3: m2.second)

ans.back().push_back(m3);

}

}

return ans;

}

};

//DFS Method