salutlu的专栏

Given two sorted integer arrays A and B, merge B into A as one sorted array. Note: You may assume that A has enough space (size that is greater or equal to m + n) to hold additional elements from

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4], the contiguous subarray [2,3] has the larges

Total Accepted: 8400 Total Submissions: 38235 My Submissions 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 profi

Convert Sorted List to Binary Search Tree   Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 想了好久想不出来，后来看了题目分类里面说是DFS，但是没有想出DFS的算法来。后来想到了

Trapping Rain Water   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. For example,  Given [0

这里有一个介绍的比较系统的Ksum文章 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,

http://blog.youkuaiyun.com/u011095253/article/details/9177451 这道题mei'you

The gray code is a binary numeral system where two successive values differ in only one bit. Given a non-negative integer n representing the total number of bits in the code, print the sequence of

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in-place? 这个for循环中的下标非常容易搞混，一定要区分清楚，到底固定哪一列，对于第二个for里面，i相当于常量

Best Time to Buy and Sell Stock II  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 ma

Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words. For example, given s = "leetcode", dict = ["leet"

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric:     1    / \   2   2  / \ / \ 3  4 4  3 But the fo

Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 刚看到

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? 刚开始看到题目简单的写了个递归，提交超时。后来又仔细推演

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,-1,2,1] ha

Given a sorted linked list, delete all duplicates such that each element appear only once. For example, Given 1->1->2, return 1->2. Given 1->1->2->3->3, return 1->2->3. 相比第一次写的代码，这次的看起来有点代码之

Implement pow(x, n). 第一感觉就是不能O(n),于是想了一个递归O(lgn)的办法，但是为了处理x和n的符号情况用了一个子函数。 发现了一个int最小值问题，这里（http://bukkake.iteye.com/blog/712953）有详细的介绍。 如果int值是（-2147483648），int的最小值，则取符号相反的情况，在VS里面是不会有变化的。但是

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, whe

Gas Station There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from st