Given an array of integers, find if the array contains any duplicates. ContainsDuplicate

Given a sorted array arr[] and a number x, write a function that counts the occurrences of x in arr[]. Count-the-number-of-occurrences-in-a-sorted-array

Find the sum of contiguous subarray within a one-dimensional array of numbers which has the largest sum. MaximumSubArray

Find the most popular element in int[] array MostFrequentInteger

Find all N! permutation of the elements of an array Permutation

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. RemoveDuplicatesFromSortedArray

• Do not allocate extra space for another array, you must do this in place with constant memory.

Given an integer x and an unsorted array of integers, describe an algorithm to determine whether two of the numbers add up to x. (without hash tables) - containsSum

Find the Maximum and minimum of an array using minimum number of comparisons. - MaxMin

Given an array of unknown size, reverse the positive numbers (before a negative marker) in the array. Ex: [2, 3, 1, 4,-1...] would become [4, 1, 3, 2, -1...] - SegregatePositiveAndNegativeNumbers

Given an array of integers, find two numbers such that they sum up to a specific target. - coupleSum

Given that integers are read from a data stream. Find median of elements read so for in efficient way. - MedianMaintenance

Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (i.e., buy one and sell one share of the stock), design an algorithm to find the maximum profit. - best-time-to-buy-and-sell-stock

Given an integer array nums, find the contiguous subarray within an array which has the largest product. maximum-product-subarray

Given an array nums of n integers where n > 1, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i] product-of-array-except-self

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. Find the minimum element. find-minimum-in-rotated-sorted-array

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). - insert-interval

Given a collection of intervals, merge all overlapping intervals. - merge-intervals

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in-place. - set-matrix-zeroes

You are given an n x n 2D matrix representing an image, inplace. Rotate the image by 90 degrees (clockwise). rotate-image

Given a matrix of m * n elements (m rows, n columns), return all elements of the matrix in spiral order. - spiralOrderMatrix

You are given a square 2D image matrix where each integer represents a pixel. Write a method transposeMatrix to transform the matrix into its Transpose - in-place. - transposeMatrix