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Algorithm Archive

I have been posting data structure and algorithms programs on various topics such as Array,Queue, Stack ,Binary tree, LinkedList , String, Number, ArrayList, etc. So I am consolidating list of programs to create an index …

Problem Given a Generic Tree, Serialize and Deserialize it. Serialization is a basically a representation of a tree in a String format which takes much lesser space than storing the tree itself. Deserialization is constructing …

In this post, we will see about Lowest Common Ancestor for n-ary Tree. Problem Given a n-ary tree also known as a Generic Tree and also two nodes. You need to find the Lowest common …

In this post, we will see how to find the local minima in the array. Problem An element is local minima if it is less than its neighbors. Solution Naive approach You can use …

In this post, we will see edit distance problem in java Problem Given two strings string1 and string2, String1 is to be converted into String2 with the given operations available in the minimum number of …

In this post, we will see about Sliding Window Maximum in java Problem Given an Array of integers and an Integer k, Find the maximum element of from all the contiguous subarrays of size K. …

In this post, we will see how to count number of occurrences (or frequency) of each element in a sorted array Problem Given a Sorted Array of integers containing duplicates. Find the frequency of every …

In this post, we will see how to find subarrays with given sum in an array. Problem Given an Array of non negative Integers and a number. You need to print all the starting and …

In this post, we will see how to find peak element in the array. Problem Given an array of integers. find the peak element in the array. Peak Element is the element of the array …

In this post, we will see how to count number of 1’s in sorted binary array. Problem Print number of 1’s in a given sorted Binary Array. For eg:- int arr = {0,0,0,1,1,1,1}; output : …

In this post, we will see how to find the first repeating element in array of integers. Problem Find the first repeating element in array of integers. For example: Input: array = {10, 7, 8, …