## Combination Sum Leetcode Solution

The problem Combination Sum Leetcode Solution provides us an array or list of integers and a target. We are told to find the combinations that can be made using these integers any number of times that add up to the given target. So more formally, we can use the given …

## Majority Element Leetcode Solution

Problem Statement   We are given an array of integers. We need to return the integer which occurs more than ⌊N / 2⌋ time in the array where ⌊ ⌋ is the floor operator. This element is called the majority element. Note that the input array always contains a majority element. …

## Insert into a Binary Search Tree Leetcode Solution

In this problem, we are given the root node of a Binary Search Tree containing integer values and an integer value of a node that we have to add in the Binary Search Tree and return its structure. After inserting the element into the BST, we have to print its …

## Permutations Leetcode Solution

The problem Permutations Leetcode Solution provides a simple sequence of integers and asks us to return a complete vector or array of all the permutations of the given sequence. So, before going into solving the problem. We should be familiar with permutations. So, a permutation is nothing but an arrangement …

This post is on Lemonade Change Leetcode Solution Problem statement   In the problem ” Lemonade Change” there is a queue of customers. They want to buy lemonade from us which costs 5 rupees. The customers can give us 5 rupees, 10 rupees, or 20 rupees. We want to return the …

## Count of index pairs with equal elements in an array

Suppose, we have given an integer array. The problem “Count of index pairs with equal elements in an array” asks to find out the no of pair of indices (i,j) in such a way that arr[i]=arr[j] and i is not equal to j. Example   arr[] = {2,3,1,2,3,1,4} 3 Explanation Pairs …

## Maximum possible difference of two subsets of an array

Suppose, we have an integer array. The problem statement “Maximum possible difference of two subsets of an array” asks to find out the maximum possible difference between the two subsets of an array. Conditions to be followed: An array can contain repeating elements, but the highest frequency of an element …

## Letter Combinations of a Phone Number

In letter combinations of a phone number problem, we have given a string containing numbers from 2 to 9. The problem is to find all the possible combinations that could be represented by that number if every number has some letters assigned to it. The assignment of the number is …

## Validate Binary Search Tree

Problem   In Validate Binary Search Tree problem we have given the root of a tree, we have to check if it is a binary search tree or not. Example : Output: true Explanation: The given tree is a binary search tree because all elements which are left to each subtree …

## Maximum Sum Increasing Subsequence

Problem Statement   In the “Maximum Sum Increasing Subsequence” problem we have given an array. Find the sum of the maximum subsequence of the given array, that is the integers in the subsequence are in sorted order. A subsequence is a part of an array which is a sequence that is …