Hello everybody, I was solving a Data-Structure Problem , Finding the Vertical Sum in a binary tree.

Vertical Sum means sum of nodes in same column.

Let me explore the question with an example.

Examples:

1 / \ 2 3 / \ / \ 4 5 6 7

The tree has 5 vertical lines

Vertical-**Line-1** has only one node 4 => **vertical sum** is 4

Vertical-**Line-2:** has only one node 2=> **vertical sum** is 2

Vertical-**Line-3:** has three nodes: 1,5,6 => **vertical sum** is 1+5+6 = 12

Vertical-**Line-4:** has only one node 3 => **vertical sum** is 3

Vertical-**Line-5:** has only one node 7 => **vertical sum** is 7

We can find this problem here [link][1] also on @geeksforgeeks.

I got the concept of **Horizontal Distance**.

My problem is how to implement Hash Map in C++ ??

In that we have keys with **-ve** values.

Please any-body explain how to implement Hash-Map in C++ .

Thanks and Happy Coding!!!

[1]: http://www.geeksforgeeks.org/vertical-sum-in-a-given-binary-tree/