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题目描述 输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构） 1 /** 2 public class TreeNode { 3 int val = 0; 4 TreeNode left = null; 5 TreeNode right = null; 6 7 阅读全文
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Given a set of distinct integers, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. Exampl 阅读全文
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Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the or 阅读全文
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Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmet 阅读全文
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Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction 阅读全文
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Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runti 阅读全文
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Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest l 阅读全文
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You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you cl 阅读全文
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Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path. 阅读全文
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A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any p 阅读全文