Blue Ocean

In-order flatten binary tree, the idea here is similar to in-order traverse of the tree, keep a pointer to previous node visited, then link ...

To do it iteratively is little bit tricky, since when we do down to the left of tree, we need to remember the way to go back to right. The...

Problem: Give two strings representing the inorder and preorder traversals of binary tree, construct the tree. The key here is that preor...

Given a Binary Tree, find the maximum sum from a leaf to root and return this leaf as well. The key is from root to leave, add up the nod...

This is a google interview question:  Divide number and return result in form of a string. e.g 100/3 result should be 33.(3) Here 3 is in ...

This is a stackoverflow question: http://stackoverflow.com/questions/1851239/permutations-for-digits-represented-by-phone-number This can ...

For example, if n=1 {} for n=2 {}{} {{}} Most of the solutions found online are using recursion. Here is the version which does iterat...