Find the surpasser count for each element of an array

Given an array of integers having distinct elements, find the surpasser count for each element in it. In other words, for each element of the array, find the number of elements to its right which are greater than it.

Construct a Binary Tree from Ancestor Matrix

Given an ancestor matrix, whose cell (i, j) has value true if i is ancestor of j in a binary tree, construct a binary tree from it where binary tree nodes are labelled from 0 to n-1 where n is the size of the ancestor matrix.

Implement Trie Data Structure in Java

Trie is a tree-based data structure used for efficient retrieval of a key in a huge set of strings. In this post, we will implement Trie data structure in Java.