Try it on GfG Practice Given an integer n. Print first n elements of Recaman’s sequence. Recaman's Sequence starts with 0 as the first term. For each next term, calculate previous term - index (if positive and not already in sequence); otherwise, use previous term + index. Examples: Input: n = 6…

Given an array of n-positive elements. The sub-array sum is defined as the sum of all elements of a particular sub-array, the task is to find the sum of all unique sub-array sum. Note: Unique Sub-array sum means no other sub-array will have the same sum value. Examples: Input : arr[] = {3, 4, 5}…

Given two same-sized arrays a[] and b[] (each containing distinct elements individually, but they may have some common elements between them). The task is to create a third array res[] of the same size n that includes maximum n elements combined from both arrays. Start by including elements from a[]…

Try it on GfG Practice Given an array of n integers. Count the total number of sub-arrays having total distinct elements, the same as that of the total distinct elements of the original array. Examples: Input : arr[] = {2, 1, 3, 2, 3} Output : 5 Total distinct elements in array is 3 Total sub-arrays…

Background : There are three basic operations that must be supported by a hash table (or a dictionary): Lookup(key): return true if key is there on the table, else falseInsert(key): add the item ‘key’ to the table if not already presentDelete(key): removes ‘key’ from the table Collisions are very…

Try it on GfG Practice Given an array of size N. Let min and max be the minimum and maximum in the array respectively. Task is to find how many number should be added to the given array such that all the element in the range [min, max] occur at-least once in the array. Examples: Input : arr[] = {4,…

Try it on GfG Practice Given two binary arrays, a1[] and a2[] of the same size n. Find the length of the longest common span (i, j) where j >= i such that a1[i] + a1[i+1] + .... + a1[j] = a2[i] + a2[i+1] + .... + a2[j]. Examples: Input: a1[] = [0, 1, 0, 0, 0, 0] a2[] = [1, 0, 1, 0, 0, 1] Output: 4…

Given an array of n non-negative integers. The task is to find frequency of a particular element in the arbitrary range of array[]. The range is given as positions (not 0 based indexes) in array. There can be multiple queries of given type. Examples: Input : arr[] = {2, 8, 6, 9, 8, 6, 8, 2, 11};…

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) from all the four arrays whose sum is equal to x. Note: The quadruple has an element from each of the four arrays. Examples: Input : arr1 = {1, 4, 5, 6}, arr2…

Given an array arr[] and a target value, the task is to find all possible indexes (i, j, k, l) of quadruplets (arr[i], arr[j], arr[k], arr[l]) whose sum is given target and all indexes in a quadruple are distinct (i != j, j != k, and k != l). We need to return indexes of a quadruple in sorted order,…

Try it on GfG Practice Given an array arr[] and a target value, the task is to find the count of quadruplets present in the given array having sum equal to the given target. Examples: Input: arr[] = [1, 5, 3, 1, 2, 10], target = 20 Output: 1 Explanation: Only quadruplet satisfying the conditions is…

Try it on GfG Practice Given two integers a and b(b != 0), the task is to return the fraction a/b in string format. If the fractional part is repeating, enclose the repeating part in parentheses. Examples: Input: a = 1, b = 2 Output: "0.5" Explanation: 1/2 = 0.5 with no repeating part. Input: a =…

Try it on GfG Practice Given an integer array arr[], print kth distinct element in this array. The given array may contain duplicates and the output should print the k-th element among all unique elements. If k is more than the number of distinct elements, print -1. Examples: Input: arr[] = {1, 2,…

Given a list of words with lower cases. Implement a function to find all Words that have the same unique character set. Example: Input: words[] = { "may", "student", "students", "dog", "studentssess", "god", "cat", "act", "tab", "bat", "flow", "wolf", "lambs", "amy", "yam", "balms", "looped",…

Try it on GfG Practice Given an array with distinct elements, the task is to find the pairs in the array such that a % b = k, where k is a given integer. You may assume that a and b are in small range Examples : Input : arr[] = {2, 3, 5, 4, 7} k = 3 Output : (7, 4), (3, 4), (3, 5), (3, 7) 7 % 4 = 3…

We are given an array consisting of n integers and an integer k. We need to find the smallest subarray [l, r] (both l and r are inclusive) such that there are exactly k different numbers. If no such subarray exists, print -1 and If multiple subarrays meet the criteria, return the one with the…

We have read about various sorting algorithms such as heap sort, bubble sort, merge sort and others. Here we will see how can we sort N elements using a hash array. But this algorithm has a limitation. We can sort only those N elements, where the value of elements is not large (typically not above…

Given an array of n-integers. The array may contain repetitive elements but the highest frequency of any element must not exceed two. You have to make two subsets such that the difference of the sum of their elements is maximum and both of them jointly contain all elements of the given array along…

Given a string of lowercase letters. Find minimum characters to be inserted in the string so that it can become palindrome. We can change the positions of characters in the string. Examples: Input: geeksforgeeks Output: 2 Explanation: geeksforgeeks can be changed as: geeksroforskeeg or…

Design a data structure that supports the following operations in O(1) time. insert(x): Inserts an item x to the data structure if not already present.remove(x): Removes item x from the data structure if present. search(x): Searches an item x in the data structure.getRandom(): Returns a random…

Try it on GfG Practice Given an array arr[], the task is to find the largest subset from array that contain elements which are Fibonacci numbers. Examples : Input: arr[] = [1, 4, 3, 9, 10, 13, 7] Output: [1, 3, 13] Explanation: The output three numbers are the only Fibonacci numbers in array. Input:…

Try it on GfG Practice Given an unsorted array of integers, find a subarray that adds to a given number. If there is more than one subarray with the sum of the given number, print any of them. Examples: Input: arr[] = {1, 4, 20, 3, 10, 5}, sum = 33 Output: Sum found between indexes 2 and 4…

Given a 2d matrix of strings arr[][] of order n * 2, where each array arr[i] contains two strings, where the first string arr[i][0] is the employee and arr[i][1] is his manager. The task is to find the count of the number of employees under each manager in the hierarchy and not just their direct…

Try it on GfG Practice Given an array arr[] and an integer k, the task is to find the length of longest subarray in which the count of elements greater than k is more than the count of elements less than or equal to k. Examples: Input: arr[]= [1, 2, 3, 4, 1], k = 2 Output: 3 Explanation: The…

Try it on GfG Practice Given an array arr[], the task is to find all possible indices {i, j, k} of triplet {arr[i], arr[j], arr[k]} such that their sum is equal to zero and all indices in a triplet should be distinct (i != j, j != k, k != i). We need to return indices of a triplet in sorted order,…

Given a matrix of distinct values and a sum. The task is to find all the pairs in a given matrix whose summation is equal to the given sum. Each element of a pair must be from different rows i.e; the pair must not lie in the same row. Examples: Input : mat[][] = {{1, 3, 2, 4}, {5, 8, 7, 6}, {9, 10,…

Given an array arr[] and a target value, the task is to find the count of triplets present in the given array having sum equal to the given target. Examples: Input: arr[] = [0, -1, 2, -3, 1], target = -2 Output: 2 Explanation: Two triplets that add up to -2 are: arr[0] + arr[3] + arr[4] = 0 + (-3) +…

Try it on GfG Practice Given an arr[] containing n integers and a positive integer k, he problem is to find the longest subarray's length with the sum of the elements divisible by k. Examples: Input: arr[] = [2, 7, 6, 1, 4, 5], k = 3 Output: 4 Explanation: The subarray [7, 6, 1, 4] has sum = 18,…

Try it on GfG Practice Given an array arr[] of size n filled with numbers from 1 to n-1 in random order. The array has only one repetitive element. The task is to find the repetitive element. Examples: Input: arr[] = [1, 3, 2, 3, 4] Output: 3 Explanation: The number 3 is the only repeating element.…

Try it on GfG Practice Given two arrays arr1[] and arr2[] consisting of n and m elements respectively. The task is to find the minimum number of elements to remove from each array such that intersection of both arrays becomes empty and both arrays become mutually exclusive. Examples: Input: arr[] =…

You are given an array of n-element. You have to make subsets from the array such that no subset contain duplicate elements. Find out minimum number of subset possible. Examples : Input : arr[] = {1, 2, 3, 4} Output :1 Explanation : A single subset can contains all values and all values are…

Try it on GfG Practice Given an array arr[] and a positive integer k, the task is to count all pairs (i, j) such that i < j and absolute value of (arr[i] - arr[j]) is equal to k. Examples: Input: arr[] = [1, 4, 1, 4, 5], k = 3 Output: 4 Explanation: There are 4 pairs with absolute difference 3, the…

Try it on GfG Practice Given two arrays a[] and b[], the task is to return union of both the arrays in any order. Note: Union of two arrays is an array having all distinct elements that are present in either array. Examples: Input : a[] = {1, 2, 3, 2, 1}, b[] = {3, 2, 2, 3, 3, 2} Output : {3, 2, 1}…

Try it on GfG Practice Given an array arr[] of n integers and a target value, the task is to find the number of pairs of integers in the array whose sum is equal to target. Examples: Input: arr[] = {1, 5, 7, -1, 5}, target = 6 Output: 3 Explanation: Pairs with sum 6 are (1, 5), (7, -1) & (1, 5).…

Try it on GfG Practice Given an array, the task is to find the most frequent element in it. If there are multiple elements that appear a maximum number of times, return the maximum element. Examples: Input : arr[] = [1, 3, 2, 1, 4, 1] Output : 1 Explanation: 1 appears three times in array which is…

Try it on GfG Practice Given two arrays a[] and b[], the task is find intersection of the two arrays. Intersection of two arrays is said to be elements that are common in both arrays. The intersection should not count duplicate elements and the result should contain items in any order. Input: a[] =…

Try it on GfG Practice Given an integer array arr[] and an integer k, determine whether there exist two indices i and j such that arr[i] == arr[j] and |i - j| ≤ k. If such a pair exists, return 'Yes', otherwise return 'No'. Examples: Input: k = 3, arr[] = [1, 2, 3, 4, 1, 2, 3, 4] Output: No…

Try it on GfG Practice Given an array arr[], the task is to find the maximum distance between two occurrences of any element. If no element occurs twice, return 0. Examples: Input: arr = [1, 1, 2, 2, 2, 1] Output: 5 Explanation: distance for 1 is: 5-0 = 5, distance for 2 is: 4-2 = 2, So max distance…

Try it on GfG Practice Given two arrays, a and b of equal length. The task is to determine if the given arrays are equal or not. Two arrays are considered equal if: Both arrays contain the same set of elements.The arrangements (or permutations) of elements may be different.If there are repeated…

Try it on GfG Practice Given two arrays a and b, check if they are disjoint, i.e., there is no element common between both the arrays. Examples: Input: a[] = {12, 34, 11, 9, 3}, b[] = {2, 1, 3, 5} Output: False Explanation: 3 is common in both the arrays. Input: a[] = {12, 34, 11, 9, 3}, b[] = {7,…