Categories of Questions

## Array Questions Directi

**Check if Array Contains Contiguous Integers With Duplicates Allowed** You are given an array of integers which can contain duplicate elements as well. The problem statement asks to find out if it is a set of contiguous integers, print “Yes” if it is, print “No” if it is not. Example Sample Input: [2, 3, 4, 1, 7, 9] Sample ...

**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 ...

**Minimum operation to make all elements equal in array** The problem “Minimum operation to make all elements equal in array” states that you are given an array with some integers in it. You have to find out the minimum operations that can be done to make an array equal. Example [ 1,3,2,4,1] 3 Explanation Either 3 subtractions can be ...

**Generate all possible sorted arrays from alternate elements of two given sorted arrays** The problem “Generate all possible sorted arrays from alternate elements of two given sorted arrays” states that suppose you have two sorted arrays. The problem statement asks to find out all the possible sorted arrays, such that number should be arranged alternatively from the two given different arrays. Example ArrA[] ...

**Difference Array | Range update query in O(1)** You are given an integer array and two types of queries, one is to add a given number in a range and the other to print the whole array. The problem “Difference Array | Range update query in O(1)” requires us to perform the range updates in O(1). Example arr[] ...

**Constant time range add operation on an array** You have given an integer array and initially, it was initialized as 0 and also given a range. The task is to add the given number in the range of the array and print the resultant array. Example arr[] = {0, 0, 0, 0, 0} Query: {(0, 2, 50), (3, ...

**Find all pairs (a, b) in an array such that a % b = k** Problem Statement The problem “Find all pairs (a, b) in an array such that a % b = k” states that you are given an array of integers and an integer value called k. The problem statement asks to find out the pair in such a way that that x ...

**Range LCM Queries** Problem Statement The problem “Range LCM Queries” states that you have an integer array and q number of queries. Each query contains the (left, right) as a range. The given task is to find out the LCM(left, right), i.e, LCM of all the number that comes in the range of ...

**Queries on XOR of greatest odd divisor of the range** Problem Statement The problem “Queries on XOR of greatest odd divisor of the range” states that you are given an array of integer and query q, each query consists of a range. The problem statement asks to find out the XOR of the greatest odd divisor within the given range ...

**Subset with sum divisible by m** Problem Statement The problem “Subset with sum divisible by m” states that you are given an array of non-negative integers and an integer m. Now you need to find if there is a subset having sum divisible by m. That is the sum of the subset should give 0 as ...

**Find pairs with given sum such that elements of pair are in different rows** Problem Statement “Find pairs with given sum such that elements of pair are in different rows” problem states that you are given a matrix of integers and a value called “sum”. The problem statement asks to find out all the pairs in a matrix that sums up to a given ...

**Maximum Subarray Sum Excluding Certain Elements** Problem Statement We are given an array, and we need to find maximum subarray sum excluding certain elements. That is, we need to find the max sum of subarray such that the subarray we are considering does not contain the elements which are told to be excluded. Example of maximum ...

**Printing brackets in Matrix Chain Multiplication Problem** Problem Statement We need to find the order of multiplication of matrices such that the number of operations involved in the multiplication of all the matrices is minimized. Then we need to print this order i.e. printing brackets in matrix chain multiplication problem. Consider you have 3 matrices A, B, ...

**Largest rectangular sub-matrix whose sum is 0** Problem Statement Find the maximum size sub-matrix in a 2D array whose sum is zero. A sub-matrix is nothing but a 2D array inside of the given 2D array. So, you have a matrix of signed integers, you need to calculate the sum of sub-matrices and find the matrix with ...

**Find Three Element From Different Three Arrays Such That a + b + c = sum** Three Sum is a problem loved by interviewers. It is a problem I was personally asked during the Amazon interview. So, without wasting any more time let us get to the problem. An array that has both positive and negative numbers. Three numbers that sum up to zero/can be modified, ...

**Find Maximum of Minimum for Every Window Size in a Given Array** Given an array a[ ] of size n. For every window size that varies from 1 to n in array print or find maximum of minimum for every window size in a given array. Example Input : a[ ] = {10, 20, 30, 50, 10, 70, 30} Output : 70 30 20 ...

## String Questions Directi

**Minimum insertions to form a palindrome with permutations allowed** The problem “Minimum insertions to form a palindrome with permutations allowed” states that you are given a String with all letters in lowercase. The problem statement asks to find out the minimum insertion of a character to a string that it can become Palindrome. The position of characters can be ...

**Check if Array Contains Contiguous Integers With Duplicates Allowed** You are given an array of integers which can contain duplicate elements as well. The problem statement asks to find out if it is a set of contiguous integers, print “Yes” if it is, print “No” if it is not. Example Sample Input: [2, 3, 4, 1, 7, 9] Sample ...

## Tree Questions Directi

**Range LCM Queries** Problem Statement The problem “Range LCM Queries” states that you have an integer array and q number of queries. Each query contains the (left, right) as a range. The given task is to find out the LCM(left, right), i.e, LCM of all the number that comes in the range of ...

## Stack Questions Directi

**Find Maximum of Minimum for Every Window Size in a Given Array** Given an array a[ ] of size n. For every window size that varies from 1 to n in array print or find maximum of minimum for every window size in a given array. Example Input : a[ ] = {10, 20, 30, 50, 10, 70, 30} Output : 70 30 20 ...

## Matrix Questions Directi

**Find pairs with given sum such that elements of pair are in different rows** Problem Statement “Find pairs with given sum such that elements of pair are in different rows” problem states that you are given a matrix of integers and a value called “sum”. The problem statement asks to find out all the pairs in a matrix that sums up to a given ...

**Printing brackets in Matrix Chain Multiplication Problem** Problem Statement We need to find the order of multiplication of matrices such that the number of operations involved in the multiplication of all the matrices is minimized. Then we need to print this order i.e. printing brackets in matrix chain multiplication problem. Consider you have 3 matrices A, B, ...

**Largest rectangular sub-matrix whose sum is 0** Problem Statement Find the maximum size sub-matrix in a 2D array whose sum is zero. A sub-matrix is nothing but a 2D array inside of the given 2D array. So, you have a matrix of signed integers, you need to calculate the sum of sub-matrices and find the matrix with ...

## Other Questions Directi

**Maximum sum of a path in a Right Number Triangle** The problem “Maximum sum of a path in a Right Number Triangle” states that you are given some integers in the form of a right number triangle. Find out the maximum sum you can achieve if you start from the top and move towards the base such that you move ...

**Cutting a Rod** Problem Statement The problem “Cutting a Rod” states that you are given a rod of some particular length and prices for all sizes of rods which are smaller than or equal to the input length. That is we know the price for rods of length from 1 to n, considering ...

**Check if any two intervals overlap among a given set of intervals** Problem Statement The problem “Check if any two intervals overlap among a given set of intervals” states that you are given some set of intervals. Each interval consists of two values, one is starting time and the other is ending time. The problem statement asks to check if any of ...

**Binomial Coefficient** Problem Statement Find the Binomial Coefficient for a given value of n and k. “In mathematics, the binomial coefficients are the positive integers that occur as coefficients in the binomial theorem. Commonly, a binomial coefficient is indexed by a pair of integers n ≥ k ≥ 0 and is written as ” – quoted from Wikipedia. Example n = 5, k ...