Every binary tree problem on CodeChef eventually asks you to reason about structure from partial information. Here is the twist: you know every node’s ID and the sum of its children’s IDs — but not which node is the root.
Problem Statement Alice has learnt factorization recently. Bob doesn’t think she has learnt it properly and hence he has decided to quiz her. Bob gives Alice a very large number and asks her to find out the number of factors of that number. To make…
There are N coins kept on the table, numbered from 0 to N – 1. Initially, each coin is kept tails up. You have to perform two types of operations
Problem Statement A positive integer is called a palindrome if its representation in the decimal system is the same when read from left to right and from right to left. For a given positive integer K of not more than 1000000 digits, write the value of the…
Problem Statement Rohit dreams he is in a shop with an infinite amount of marbles. He is allowed to select n marbles. There are marbles of k different colors. From each color there are also infinitely many marbles. Rohit wants to have at least one…
Problem Statement Little kids, Jack and Evan like playing their favorite game Glass-and-Stone. Today they want to play something new and came across Twitter on their father’s laptop. They saw it for the first time but were already getting bored to see a bunch of…
Problem Statement In Byteland they have a very strange monetary system. Each Bytelandian gold coin has an integer number written on it. A coin n can be exchanged in a bank into three coins: n/2, n/3 and n/4. But these numbers are all rounded down…
