Try it on GfG Practice Given a sorted array and a value x, find index of the ceiling of x. The ceiling of x is the smallest element in an array greater than or equal to x. Note: In case of multiple occurrences of ceiling of x, return the index of the first occurrence. Examples : Input: arr[] = [1,…

Try it on GfG Practice Given three sorted arrays in non-decreasing order, print all common elements in non-decreasing order across these arrays. If there are no such elements return an empty array. In this case, the output will be -1. Note: In case of duplicate common elements, print only once.…

Try it on GfG Practice Given an unsorted array of size n. Array elements are in the range of 1 to n. One number from set {1, 2, ...n} is missing and one number occurs twice in the array. The task is to find these two numbers. Examples: Input: arr[] = {3, 1, 3} Output: 3, 2 Explanation: In the array,…

Try it on GfG Practice Given an integer array arr[], the task is to find the maximum sum of two elements such that sum is closest to zero. Note: In case if we have two of more ways to form sum of two elements closest to zero return the maximum sum. Examples: Input: arr[] = [-8, 5, 2, -6] Output: -1…

Given a binary array arr[] of size n, which is sorted in non-increasing order, count the number of 1's in it. Examples: Input: arr[] = [1, 1, 0, 0, 0, 0, 0] Output: 2 Explanation: Count of the 1's in the given array is 2. Input: arr[] = [1, 1, 1, 1, 1, 1, 1] Output: 7 Input: arr[] = [0, 0, 0, 0, 0,…

Try it on GfG Practice Given an array arr. The task is to find the largest element in the given array. Examples: Input: arr[] = [10, 20, 4] Output: 20 Explanation: Among 10, 20 and 4, 20 is the largest. Input: arr[] = [20, 10, 20, 4, 100] Output: 100 Table of Content Iterative Approach - O(n) Time…

Try it on GfG Practice Given an array of integers arr[], The task is to find the index of first repeating element in it i.e. the element that occurs more than once and whose index of the first occurrence is the smallest. Examples: Input: arr[] = {10, 5, 3, 4, 3, 5, 6} Output: 5 Explanation: 5 is the…

List.BinarySearch(T) Method uses a binary search algorithm to locate a specific element in the sorted List or a portion of it. There are 3 methods in the overload list of this method as follows: BinarySearch(T)BinarySearch(T, IComparer)BinarySearch(Int32, Int32, T, IComparer) BinarySearch(T) Method…

The bisect module in Python helps you efficiently maintain a sorted list by finding the correct position to insert an element, keeping the list sorted without needing to sort it again. This is useful because it reduces the overhead of repeatedly sorting the list after each insertion, making your…

java.util.Collections.binarySearch() method is a java.util.Collections class method that returns the position of an object in a sorted list. // Returns index of key in a sorted list sorted in // ascending order public static int binarySearch(List slist, T key) // Returns index of key in a sorted…

Arrays.binarySearch()| Set 1 Covers how to find an element in a sorted array in Java. This set will cover "How to Search a key in an array within a given range including only start index". Syntax : public static int binarySearch(data_type[] arr, int fromIndex, int toIndex, data_type key) Parameters…

In Java, the Arrays.binarySearch() method searches the specified array of the given data type for the specified value using the binary search algorithm. The array must be sorted by the Arrays.sort() method before making this call. If it is not sorted, the results are undefined. Example: Below is a…

Try it on GfG Practice Two pointers is really an easy and effective technique that is typically used for Two Sum in Sorted Arrays, Closest Two Sum, Three Sum, Four Sum, Trapping Rain Water and many other popular interview questions. Given a sorted array arr (sorted in ascending order) and a target,…

Try it on GfG Practice Given an array arr[] of size n-1 with distinct integers in the range of [1, n]. This array represents a permutation of the integers from 1 to n with one element missing. Find the missing element in the array. Examples: Input: arr[] = [8, 2, 4, 5, 3, 7, 1] Output: 6…

Try it on GfG Practice Given an array arr[], the task is to find the top three largest distinct integers present in the array. Note: If there are less than three distinct elements in the array, then return the available distinct numbers in descending order. Examples : Input: arr[] = [10, 4, 3, 50,…

Try it on GfG Practice Given an array, arr of n integers, and an integer element x, find whether element x is present in the array. Return the index of the first occurrence of x in the array, or -1 if it doesn't exist. Input: arr[] = [1, 2, 3, 4], x = 3 Output: 2 Explanation: There is one test case…

In C++, STL provide various functions like std::binary_search(), std::lower_bound(), and std::upper_bound() which uses the the binary search algorithm for different purposes. These function will only work on the sorted data. There are the 3 binary search function in C++ STL: Table of Content…

Try it on GfG Practice Given an array of positive integers arr[] of size n, the task is to find second largest distinct element in the array. Note: If the second largest element does not exist, return -1. Examples: Input: arr[] = [12, 35, 1, 10, 34, 1] Output: 34 Explanation: The largest element of…

Try it on GfG Practice Given an array of integers, find sum of array elements using recursion. Examples: Input: arr = [1, 2, 3] Output: 6 Explanation: 1 + 2 + 3 = 6 Input: arr = [15, 12, 13, 10] Output: 50 Explanation: 15 + 12 + 13 + 10 = 50 We have discussed iterative solution in this Post Sum of…

Given a decimal number as input, we need to write a program to convert the given decimal number into an equivalent binary number. Examples : Input: d = 7 Output: 111 Explanation: 20 + 21 + 22 = 1+2+4 = 7. Input: d = 10 Output: 1010 Explanation: 21 + 23 = 2+8 = 10. We previously discussed an…

Given a number n, find sum of first n natural numbers. To calculate the sum, we will use a recursive function recur_sum(). Examples : Input : 3 Output : 6 Explanation : 1 + 2 + 3 = 6 Input : 5 Output : 15 Explanation : 1 + 2 + 3 + 4 + 5 = 15 Below is code to find the sum of natural numbers up to n…

Try it on GfG Practice You are given an integer N. Print numbers from N to 1 without the help of loops. Examples: Input: N = 5 Output: 5 4 3 2 1 Explanation: We have to print numbers from 5 to 1. Input: N = 10 Output: 10 9 8 7 6 5 4 3 2 1 Explanation: We have to print numbers from 10 to 1. Approach:…

Try it on GfG Practice You are given an integer n. Print numbers from 1 to n without the help of loops. Examples: Input: N = 5 Output: 1 2 3 4 5 Explanation: We have to print numbers from 1 to 5. Input: N = 10 Output: 1 2 3 4 5 6 7 8 9 10 Explanation: We have to print numbers from 1 to 10. Approach:…

Given two integers N and K, the task is to generate all positive integers with length N having an absolute difference of adjacent digits equal to K. Examples: Input: N = 4, K = 8 Output: 1919, 8080, 9191 Explanation:The absolute difference between every consecutive digit of each number is 8. For…

Try it on GfG Practice Given a string s, find all possible ways to partition it such that every substring in the partition is a palindrome. Examples: Input: s = "geeks" Output: [[g, e, e, k, s], [g, ee, k, s]] Explanation: [g, e, e, k, s] and [g, ee, k, s] are the only partitions of "geeks" where…

Try it on GfG Practice Given a Binary Tree, the task is to print the Right view of it. The right view of a Binary Tree is a set of rightmost nodes for every level. Examples: Example 1: The Green colored nodes (1, 3, 5) represents the Right view in the below Binary tree. Example 2: The Green colored…

Given a stack, the task is to sort it using recursion. Example: Input: [3 2 1] Output: [3 2 1] Explanation: The given stack is sorted know 3 > 2 > 1 Input: [11 2 32 3 41] Output: [41 32 11 3 2] The main idea is to repeatedly pop elements from the stack and sort the remaining stack. After sorting the…

Try it on GfG Practice Given two strings s1 and s2 of equal length, the task is to determine if s2 is a scrambled version of s1. A scrambled string is formed by recursively splitting the string into two non-empty substrings and rearranging them randomly (s = x + y or s = y + x) and then recursively…

Given a doubly linked list. Reverse it using recursion. Original Doubly linked list Reversed Doubly linked list We have discussed Iterative solution to reverse a Doubly Linked List Algorithm: If list is empty, return Reverse head by swapping head->prev and head->next If prev = NULL it means that…

Given a number n and its reverse r. The task is to find the number obtained when the number is raised to the power of its own reverse. The answer can be very large, return the result modulo 109+7. Examples: Input : n = 2, r = 2 Output: 4 Explanation: Number 2 raised to the power of its reverse 2…

Try it on GfG Practice Given a number n, print all combinations of balanced parentheses of length n. Note: A sequence of parentheses is balanced if every opening bracket ( has a corresponding closing bracket ) in the correct order. Examples: Input: n = 2 Output: ["( )"] Explanation: Only one valid…

Given a Binary Tree, the task is to print the bottom view from left to right using Recursion. Note: If there are multiple bottom-most nodes for a horizontal distance from the root, then the latter one in the level traversal is considered. Examples: Example1: The Green nodes represent the bottom view…

Given a string str representing a string, the task is to convert the given string into an integer. Examples: Input: str = "1235" Output: 1235 Explanation: "1235" is converted to the integer 1235 by extracting and combining its digits. Input: str = "0145" Output: 145 Approach To recursively converts…

Given an integer n, we need to find the geometric sum of the following series using recursion. 1 + 1/3 + 1/9 + 1/27 + ... + 1/(3n) Examples: Input: n = 5 Output: 1.49794 Explanation: 1 + 1/3 + 1/9 + 1/27 + 1/81 + 1/243 = 1.49794 Input: n = 7 Output: 1.49977 Approach: To find the geometric sum of the…

Given two numbers N and r, find the value of NCr using recursion Examples: Input: N = 5, r = 2 Output: 10 Explanation: The value of 5C2 is 10 Input: N = 3, r = 1 Output: 3 Approach 1: One very interesting way to find the C(n,r) is the recursive method which is based on the recursive equation. C(n,r)…

Tower of Hanoi is a mathematical puzzle where we have three rods and n disks. The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules: 1) Only one disk can be moved at a time. 2) Each move consists of taking the upper disk from one of the stacks and…

Try it on GfG Practice Tower of Hanoi is a mathematical puzzle where we have three rods (A, B, and C) and N disks. Initially, all the disks are stacked in decreasing value of diameter i.e., the smallest disk is placed on the top and they are on rod A. The objective of the puzzle is to move the…

Given a string S, the task is to find the length of the longest sub-string which is a palindrome Examples: Input: S = "aaaabbaa" Output: 6 Explanation: Sub-string "aabbaa" is the longest palindromic sub-string. Input: S = "banana" Output: 5 Explanation: Sub-string "anana" is the longest palindromic…

This article is aimed at giving a recursive implementation for pattern printing. Simple triangle pattern: C++ // C++ code to demonstrate star pattern #include using namespace std; // function to print a row void printn(int num) { // base case if (num == 0) return; cout << "* "; // recursively…

Given two numbers x and y find the product using recursion. Examples : Input : x = 5, y = 2 Output : 10 Input : x = 100, y = 5 Output : 500 To find the product of two numbers x and y using recursion, you can use the following approach: Base Case: If y=0, return 0 (since any number multiplied by 0 is…