摘要：1. 问题描述 189. Rotate ArrayRotate an array of n elements to the right by k steps.For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated 阅读全文

摘要：1. 问题描述 Determine whether an integer is a palindrome. Do this without extra space.Some hints:Could negative integers be palindromes? (ie, -1)If you ar 阅读全文

摘要：1. 问题描述 Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return[[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1] 阅读全文

摘要：1. 问题描述 Given an integer n, return the number of trailing zeroes in n!.Note: Your solution should be in logarithmic time complexity.Tags: MathSimilar 阅读全文

摘要：1. 问题描述 Write a function that takes a string as input and reverse only the vowels of a string. Note:The vowels does not include the letter "y".Tags: T 阅读全文

摘要：1. 问题描述 Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.If the la 阅读全文

摘要：1. 问题描述 Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if 阅读全文

摘要：1. 问题描述 Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Note: You may assume the s 阅读全文

摘要：1. 问题描述 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 阅读全文

摘要：1. 问题描述 Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). Note: Bonus points if you could solve it both r 阅读全文

摘要：1. 问题描述 You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint sto 阅读全文

摘要：1. 问题描述 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 t 阅读全文

摘要：1. 问题描述 Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wi 阅读全文

摘要：1. 问题描述 Write a program to check whether a given number is an ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. 阅读全文

摘要：1. 问题描述 Write an algorithm to determine if a number is "happy".A happy number is a number defined by the following process: Starting with any positive 阅读全文

摘要：1. 问题描述 Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?Tags: Linked List Two PointersSimi 阅读全文

摘要：1. 问题描述 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 阅读全文

摘要：1. 问题描述 Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.Tags：Two Pointers 阅读全文

摘要：1. 问题描述 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 give 阅读全文

摘要：1. 问题描述 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.Tags：B 阅读全文