# Category Archives: Arrays

View algorithms on Arrays

## Maximum sum of elements in two non-overlapping contiguous sub arrays

Question: Given an array A, find the sum of maximum sum of two non-overlapping subarrays, with lengths L and M. In other words, return the largest V for which V = (A[i] + A[i+1] …. A[i+L-1]) + (A[j] + A[j+1] …. A[j+M-1]) Input: A = {3, 8, 1, 3, 2, 1, 8, 9, 0}; L = 3, M… Read More »

## Array Nesting

Question: Given a zero-indexed array ‘A’ of length ‘N’ which contains all integers from 0 to N-1. Find and return the longest length of set S, where S[i] = {A[i], A[A[i]], A[A[A[i]]], …} subjected to a particular condition. Suppose the first element in S starts with the selection of element A[i] of index = i, the next element… Read More »

## Container with maximum water

Question: Let us suppose we have a two dimensional plane where the the length of lines determine the height of a container. We need to determine the maximum capacity of water this kind of an arrangement can hold. The heights are represented by an array. Input: [1, 8, 6, 2, 5, 4, 8, 3, 7] Output: 49 Let… Read More »

## Largest number in an array that is at least twice of others

Question: Given an array, there is a largest element N. Check if that number is at least twice than all the other elements in the array. Return the index if it is, else return -1 Input: {3, 6, 1, 0} Output: -1 6 is the largest integer, and for every other number in the array x, 6 is… Read More »

## Next Greater Element in an array. [NGE]

Question: There is an array A[N] of N numbers. You have to compose an array Output[N] such that each element in Output[i] will tell the next greater element to the right in the original array. If there is no greater number to the right, then the output array should contain -1 in that position. Array 1: {4, 6,… Read More »

## Kth largest element in an array (Method 1)

Question: Given an unsorted array of integers and a number ‘k’. Return the kth largest element in the array. Input: arr = {3,2,1,5,6,4}, k = 2 Output: 5 Given an unsorted array of integers, you need to determine the kth largest element. By taking a first glance at the problem we can be sure of one thing. If… Read More »

## Convert a number into a string of words

Question: Given an integer N, convert it into a string of words. Input: N = 345 Output: three hundred forty five This is one of the most common problems that we come across in out daily lives. We need to input a number from the user and print it in words. First, we perform a number of checks… Read More »

## Given a function that generates random number from 1-7, write a function that generates random numbers from 1-10.

Question: You are given a function rand7() – that generates random numbers from 1-7. Write a function rand10() – that uses rand7() to generate random numbers from 1-10. This appear to be one of those probabilistic analysis questions. You should be familiar with the concept of expected value, as it could be extremely helpful in probabilistic analysis. Hint:… Read More »

## An array puzzle

Question: There is an array A[N] of N numbers. You have to compose an array Output[N] such that Output[i] will be equal to multiplication of all the elements of A[N] except A[i]. Solve it without division operator and in O(n). For example Output will be multiplication of A to A[N-1] and Output will be multiplication of A and… Read More »

## Find the intersection points of 2 sorted arrays.

Question: Given 2 sorted arrays, find the intersection elements between them. Array 1: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26 Array 2: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33 Output: 6, 12, 18, 24 Let’s called Array1 as “A” and Array2 as “B”, each with size m and… Read More »