描述: Given an array of integers, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note t…

Path Sum 题目链接 题目要求: 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 tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 /…

Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. 英文不好,简单翻译一下,能自己翻译的跳过,看不懂我的翻译自行结合翻译网站…

  Example: Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + nums[1] = 2 + 7 = 9, return [0, 1]. Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would h…

LeetCode : two sum 第一次写博客,算是熟悉这些编辑环境吧,本来是打算在csdn上用markdown写的,结果改了博客介绍就被关闭了,晕死...好了,话不多说,今天打算拿LeetCode上的第一题:Two Sum来分享试验一下. 题目描述:Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume t…

昨天在leetcode做题的时候做到了371,原题是这样的: 371. Sum of Two Integers Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -. Example: Given a = 1 and b = 2, return 3. 因为之前完全没有在实际练习中使用过位运算,所以刚看到这道题目的时候我的第一反应是 1.用乘除代替加减,但是一想,…

Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 这道求二叉树的最大路径和是一道蛮有难度的题,难就难在起始位置和结束位置可以为任意位置,我当然是又不会了,于是上网看看大神们的解法,看了很多人的都没太看明白,最后发现了网友Yu's…

转自  http://tech-wonderland.net/blog/summary-of-ksum-problems.html 前言: 做过leetcode的人都知道, 里面有2sum, 3sum(closest), 4sum等问题, 这些也是面试里面经典的问题, 考察是否能够合理利用排序这个性质, 一步一步得到高效的算法. 经过总结, 本人觉得这些问题都可以使用一个通用的K sum求和问题加以概括消化, 这里我们先直接给出K Sum的问题描述和算法(递归解法), 然后将这个一般性的方法套用…

Given an integer array nums, return the number of range sums that lie in [lower, upper] inclusive.Range sum S(i, j) is defined as the sum of the elements in nums between indices i and j (i ≤ j), inclusive. Note:A naive algorithm of O(n2) is trivial.…

Work out the first ten digits of the sum of the following one-hundred 50-digit numbers. 371072875339021027987979982208375902465101357402504637693767749000971264812489697007805041701826053874324986199524741059474233309513058123726617309629919422133635…