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原创课本8.19 kite问题的NP完全问题证明

题目描述： A kite is a graph on an even number of vertices, say 2n, in which n of the vertices form a clique and the remaining n vertices are connected in a “tail” that consists of a path joined to one

2017-07-16 21:38:47 620

原创 338. Counting Bits

题目描述： Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and return them as an array. Example:

2017-06-11 17:32:02 228

原创 64. Minimum Path Sum

题目描述： 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. Note: You can only move either down

2017-06-04 23:30:41 192

原创 96. Unique Binary Search Trees

题目描述： Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example, Given n = 3, there are a total of 5 unique BST's. 1 3 3 2

2017-05-30 00:13:57 199

原创 70. Climbing Stairs

题目描述： 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 climb to the top? Note: Given n wil

2017-05-20 12:01:57 213

原创 303. Range Sum Query - Immutable

题目描述： Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Given nums = [-2, 0, 3, -5, 2, -1] sumRange(0, 2) -> 1 sumRange(2, 5) -

2017-05-13 23:42:51 170

原创 198. House Robber

题目描述： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adj

2017-05-07 21:22:23 154

原创 121. Best Time to Buy and Sell Stock

题目描述： 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 (ie, buy one and sell one share of

2017-04-26 22:47:59 166

原创 122. Best Time to Buy and Sell Stock II

题目描述： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like

2017-04-23 17:38:01 169

原创 455. Assign Cookies

题目描述： Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie. Each child i has a greed factor gi, which is the minimum

2017-04-16 16:58:42 154

原创 107. Binary Tree Level Order Traversal II

题目描述： Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For example: Given binary tree [3,9,20,

2017-04-08 22:21:54 187

原创 111. Minimum Depth of Binary Tree

题目描述： Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 解题思路：本题用BFS的算法，同时向左右子结点

2017-04-01 23:55:11 163

原创 112. Path Sum

题目描述： Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tr

2017-03-26 18:58:37 158

原创 399. Evaluate Division

题目描述： Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers.

2017-03-20 13:14:40 193

原创 53. Maximum Subarray

题目描述： Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2,1,-5,4], the contiguous subarray [4

2017-03-12 22:57:38 275

原创 169. Majority Element

题目描述： Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majori

2017-03-05 20:53:20 152

原创 485. Max Consecutive Ones

题目描述： Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Input: [1,1,0,1,1,1] Output: 3 Explanation: The first two digits or the last three digits are c

2017-02-26 11:26:11 187

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