摘要：
Given a set of distinct integers, nums, return all possible subsets. Note: The solution set must not contain duplicate subsets. For example, If nums = 阅读全文
摘要：
Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. For example, If n = 4 and k = 2, a solution is: [ [2,4], [3, 阅读全文
摘要：
Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). For example, S = "ADOBECO 阅读全文
摘要：
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: + Integers in each row are sorted 阅读全文