# Category Archives: Hash

## Concatenated string with uncommon characters of two stringsSeptember 2, 2017

Two strings are given and you have to modify 1st string such that all the common characters of the 2nd strings have to be removed… Read More »

## Smallest element repeated exactly ‘k’ times (not limited to small range)August 30, 2017

Given an array of size n, the goal is to find out the smallest number that is repeated exactly ‘k’ times where k > 0?… Read More »

## Find All Duplicate SubtreesAugust 14, 2017

Given a binary tree, find all duplicate subtrees. For each duplicate subtrees, we only need to return the root node of any one of them.… Read More »

## Minimum number of distinct elements after removing m itemsAugust 6, 2017

Given an array of items, an i-th index element denotes the item id’s and given a number m, the task is to remove m elements… Read More »

## Maximum possible sum of a window in an array such that elements of same window in other array are uniqueAugust 4, 2017

Given two arrays A and B of equal number of elements. Task is to find the maximum sum possible of a window in array B… Read More »

## Find top k (or most frequent) numbers in a streamJuly 29, 2017

Given an array of n numbers. Your task is to read numbers from the array and keep at-most K numbers at the top (According to… Read More »

## Minimum Index Sum for Common Elements of Two ListsJuly 28, 2017

Ram and Shyam want to choose a website to learn programming and they both have a list of favorite websites represented by strings. You need… Read More »

## Find any one of the multiple repeating elements in read only array

Given a read only array of size ( n+1 ), find one of the multiple repeating elements in the array where the array contains integers… Read More »

## Hash Table vs STL MapJuly 13, 2017

This article focus on : Compare and contrast Hash table and an STL Map. How is the hash table implemented? If the number of inputs… Read More »

## All unique triplets that sum up to a given valueJuly 6, 2017

Given an array and a sum value, find all possible unique triplets in that array whose sum is equal to the given sum value. If… Read More »

## Minimum insertions to form a palindrome with permutations allowedJuly 5, 2017

Given a string of lowercase letters. Find minimum characters to be inserted in string so that it can become palindrome. We can change positions of… Read More »

## Find four elements that sum to a given value | Set 3 (Hashmap)

Given an array of integers, Check if there exist four elements at different indexes in the array whose sum is equal to a given value… Read More »

## Count quadruples from four sorted arrays whose sum is equal to a given value xJuly 4, 2017

Given four sorted arrays each of size n of distinct elements. Given a value x. The problem is to count all quadruples(group of four numbers)… Read More »

## Count pairs from two linked lists whose sum is equal to a given valueJuly 3, 2017

Given two linked lists(can be sorted or unsorted) of size n1 and n2 of distinct elements. Given a value x. The problem is to count… Read More »

## Nuts & Bolts Problem (Lock & Key problem) | Set 2 (Hashmap)July 2, 2017

Given a set of n nuts of different sizes and n bolts of different sizes. There is a one-one mapping between nuts and bolts. Match… Read More »