James Pan

原题网址：https://leetcode.com/problems/find-the-duplicate-number/ Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate nu

原题网址：https://leetcode.com/problems/longest-increasing-subsequence/ Given an unsorted array of integers, find the length of longest increasing subsequence. For example, Given [10, 9, 2, 5, 3,

原题网址：https://leetcode.com/problems/remove-invalid-parentheses/ Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results. Note: The

原题网址：https://leetcode.com/problems/permutations-ii/ Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the followi

原题网址：https://leetcode.com/problems/shortest-palindrome/ Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrom

原题网址：https://leetcode.com/problems/range-addition/ Assume you have an array of length n initialized with all 0's and are given k update operations. Each operation is represented as a triplet: 

原题网址：https://leetcode.com/problems/minimum-height-trees/ For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all po

原题网址：https://leetcode.com/problems/russian-doll-envelopes/ You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and on

原题网址：https://leetcode.com/problems/count-of-smaller-numbers-after-self/ You are given an integer array nums and you have to return a new counts array. The counts array has the property where coun