A peak element is an element that is greater than its neighbors.
Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.
Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
Given a non-empty array of integers, every element appears twice except for one. Find that single one.
Given a binary search tree, write a function kthSmallest to find the kth smallest element in it.
Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element.
Given an array of integers, find if the array contains any duplicates.
Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times.