摘要： Given a collection of numbers that might contain duplicates, return all possible unique permutations. Example: 有重复数字的情况，之前在Subsets II，我们采取的是在某一个递归内，用f 阅读全文

摘要： Given a collection of distinct integers, return all possible permutations. Example: 规律：类似插入排序，每个数都有多个可插入的位置。 递归的时候：循环插入的位置。递归结束条件：插入到最后一个数。 阅读全文

摘要： Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maxim 阅读全文

摘要： Given two non-negative integers num1 and num2represented as strings, return the product of num1 and num2, also represented as a string. Example 1: Exa 阅读全文

摘要： Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining. 阅读全文

摘要： Given an unsorted integer array, find the smallest missing positive integer. Example 1: Example 2: Example 3: Note: Your algorithm should run in O(n) 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 an array of integers nums sorted in ascending order, find the starting and ending position of a given targetvalue. Your algorithm's runtime comp 阅读全文

摘要： Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such arrangement is not possib 阅读全文