Given an array of integers, replace every element with the next greatest element (greatest element on the right side) in the array. Since there is no element next to the last element, replace it with -1. For example, if the array is [16, 17, 4, 3, 5,…

2. Add Two Numbers[medium] You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You…

92. Reverse Linked List II[Medium] Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:Given m, n satisfy the fo…

82. Remove Duplicates from Sorted List II[Medium] Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. For example,Given 1->2->3->3->4->4->5, return 1->2->5…

61. Search for a Range[medium] Given a sorted array of n integers, find the starting and ending position of a given target value. If the target is not found in the array, return [-1, -1]. Have you met this question in a real interview? Yes Example Gi…

62. Search in Rotated Sorted Array[medium] Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, ot…

74. First Bad Version [medium] The code base version is an integer start from 1 to n. One day, someone committed a bad version in the code case, so it caused this version and the following versions are all failed in the unit tests. Find the first bad…

75. Find Peak Element [medium] There is an integer array which has the following features: The numbers in adjacent positions are different. A[0] < A[1] && A[A.length - 2] > A[A.length - 1]. We define a position P is a peek if: A[P] > A[P-…

159. Find Minimum in Rotated Sorted Array [medium] Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. Notice You may assume no duplicate exists in the…

There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair: [0,1] Given the total number of courses and a l…