Medium
Solutions and thought process for medium difficulty Leetcode problems.
287. Find the Duplicate Number
Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
2. Add Two Numbers
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 contains a single digit. Add the two numbers and return the sum as a linked list.
138. Copy List with Random Pointer
A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null.
153. Find Minimum in Rotated Sorted Array
Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7] might become:
853. Car Fleet
There are n cars at given miles away from the starting mile 0, traveling to reach the mile target.
739. Daily Temperatures
Given an array of integers temperatures represents the daily temperatures, return an array answer such that answer[i] is the number of days you have to wait after the ith day to get a warmer temperature. If there is no future day for which this is possible, keep answer[i] == 0 instead.
22. Generate Parentheses
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
15. 3Sum
Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.
11. Container With Most Water
You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).
150. Evaluate Reverse Polish Notation
You are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation.