LimingLiuLiming-优快云博客

原创 Set Matrix Zeroes

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.Have you met this question in a real interview? YesExampleGiven a matrix[ [1,2],

2015-10-06 21:50:43 684

Given string A representative a positive integer which has N digits, remove any k digits of the number, the remaining digits are arranged according to the original order to become a new positive integ

2015-09-07 20:20:05 577

原创 Continuous Subarray Sum II

Given an integer array, find a continuous rotate subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are

2015-09-01 10:35:53 703

原创 Best Time to Buy and Sell Stock III

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 at most twotransactions.Have you met t

2015-08-24 22:30:37 446

原创 Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never diffe

2015-08-24 20:24:55 499

原创 strStr

strstr (a.k.a find sub string), is a useful function in string operation. Your task is to implement this function.For a given source string and a target string, you should output the firstindex(fr

2015-08-12 18:50:21 1193

原创 Product of Array Exclude Itself

Given an integers array A.Define B[i] = A[0] * ... * A[i-1] * A[i+1] * ... * A[n-1], calculate B WITHOUT divide operation.Have you met this question in a real interview? YesExamp

2015-08-09 15:35:00 480

原创 Triangle

Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.Have you met this question in a real interview? YesExamp

2015-08-09 15:14:54 423

原创 Recover Rotated Sorted Array

Given a rotated sorted array, recover it to sorted array in-place.Have you met this question in a real interview? YesExample[4, 5, 1, 2, 3] -> [1, 2, 3, 4, 5]Challenge

2015-08-05 15:49:29 451

原创 Flip Bits

Determine the number of bits required to flip if you want to convert integer n to integer m.Have you met this question in a real interview? YesExampleGiven n = 31 (11111), m = 14

2015-08-05 14:49:47 808

原创 Subtree

You have two every large binary trees: T1, with millions of nodes, and T2, with hundreds of nodes. Create an algorithm to decide if T2 is a subtree of T1.Have you met this question in a real

2015-08-05 11:15:43 560

原创 Remove Element

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.此

2015-08-02 15:59:48 333

原创 Remove Duplicates from Sorted Array

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.Do not allocate extra space for another array, you must do this in place with

2015-08-02 15:23:46 341

原创 Reverse Nodes in k-Group

Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end should remain as it is

2015-08-02 14:40:40 441

原创 Swap Nodes in Pairs

Given a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2->1->4->3.Your algorithm should use only constant space. Y

2015-08-02 10:43:45 449

原创 Merge k Sorted Lists

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.类似于归并排序的处理，这里将一个个链表看成一个个有序的元素。/** * Definition for singly-linked list. * struct ListNode { *

2015-08-02 10:29:26 323

原创 Generate Parentheses

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:"((()))", "(()())", "(())()", "()(())", "()()()

2015-08-02 09:49:00 342

原创 Letter Combinations of a Phone Number

Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is given below.Input:Digit st

2015-08-01 22:28:19 451

原创 3Sum Closest

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exact

2015-08-01 22:07:19 321

原创 3Sum

Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.Note:Elements in a triplet (a,b,c

2015-08-01 21:25:24 409

原创 Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.求解最长公共前缀，看到第一反应是用trie树，简历一颗trie树，然后查找下，某个点的计数次数是不是等于len，不等于则停止，等于则加入公共前缀字符串，继续查找。class TrieNode {public:

2015-08-01 18:46:43 349

原创 Roman to Integer

Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.和整数转罗马数字一样，根据转换规则转换。class Solution {public: //分析最近的两个字符，如果i字符比i-1字符小，那么此时应该是s

2015-08-01 18:09:33 316

原创 Integer to Roman

Given an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999.此题找规律模拟操作，分析1-10的整数是如何构造出罗马数字的，然后再依葫芦画瓢，注意细节的处理。class Solution {public: string In

2015-08-01 17:54:11 326

原创 Container With Most Water

Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Fin

2015-08-01 17:34:54 307

原创 Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negative integers be palindromes? (ie, -1)If you are thinking of convertin

2015-08-01 17:15:05 322

原创 String to Integer (atoi)

Implement atoi to convert a string to an integer.Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input ca

2015-08-01 17:07:46 498

原创 Reverse Integer

Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321对于数值问题，首先一定要记住，一定要时刻注意溢出问题，这个题目不难，就是要注意对于x >= INT_MAX 或者 x class Solution {public: //边求每一位，边反转

2015-08-01 16:35:20 386

原创 ZigZag Conversion

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H NA P L S I

2015-08-01 16:24:55 278

原创 Longest Palindromic Substring

Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring. 题目最暴力的方法是，枚举字

2015-08-01 16:06:33 346

原创 Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. Fo

2015-07-31 15:52:03 395

原创 Two Sum

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

2015-07-31 14:56:51 277

原创 Add Two Numbers

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a link

2015-07-31 14:48:04 377

原创 Median of Two Sorted Arrays

There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).中位数是第K个数，K = (m + n)/2,，不

2015-07-31 10:51:37 345

原创 Jump Game II

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Your goal i

2015-07-29 10:57:22 293

原创 Course Schedule

There are a total of n courses you have to take, labeled from 0 to n - 1.Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as

2015-07-17 00:02:16 330

原创 Number of Digit One

Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.For example:Given n = 13,Return 6, because digit 1 occurred in the follow

2015-07-16 16:29:40 474

原创 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 station i to

2015-07-07 22:55:09 329

原创 Restore IP Addresses

Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example:Given "25525511135",return ["255.255.11.135", "255.255.111.35"]. (Order

2015-06-21 20:37:07 447

原创 Jump Game

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Determine i

2015-05-15 17:21:12 357

原创 Subsets II

Given a collection of integers that might contain duplicates, nums, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must not contain du

2015-05-15 16:42:23 572

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