摘要： Given a collection of numbers that might contain duplicates, return all possible unique permutations. Example: 题意： 打印全排列，注明了给定序列可含有重复元素 Solution1: Bac 阅读全文

摘要： Backtracking is an algorithm for finding all solutions by exploring all potential candidates. If the solution candidate turns to be not a solution (or 阅读全文

摘要： You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Note: You have to rotate the image in-place, which 阅读全文

摘要： Given an array of strings, group anagrams together. Example: 题意： 给定一堆单词，把变位词放一块儿去。 碎碎念： 开始想说“eat” 转charArray {'e', 'a', 't'} “tea” 转charArray {'t', 'e 阅读全文

摘要： Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numb 阅读全文

摘要： Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the 阅读全文

摘要： Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in or 阅读全文

摘要： Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Example 2: Cla 阅读全文

摘要： Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. k is a positive integer and is less than or equal to 阅读全文

摘要： Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes, only nodes itself may be ch 阅读全文