Given a sorted Alien dictionary, find order of characters

In an alien language, surprisingly, they also use English lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters. Given a sequence of words written in the alien language, find the order of the alphabet. Problem statement: GeeksforGeeks Problem Link Example 1: Input: words = [“hello”,”leetcode”], order = “hlabcdefgijkmnopqrstuvwxyz”Explanation: […]

Topological Sort [Hackerearth]

A Topological sort of a Directed-Acyclic graph G is a linear ordering of all its vertices such that if G contains an edge E (u,v), then u appears before v in the ordering. And if the graph is not acyclic, then no linear ordering is possible. A topological sort of a […]

Competitive Programming (Draughts) | CodeChef

This problem was asked in February challenge 2014. Around 900 people were able to solve this problem during challenge duration. It’s a nice problem requiring the knowledge of graphs. It’s not very intuitive for beginners. And also not very straightforward for someone not doing competitive programming. Here’s the problem link: Codechef […]