hongxiuzhe

题目Given an integer, write a function to determine if it is a power of two.我的解法public class Solution { public boolean isPowerOfTwo(int n) { if(n == 0) return false;

题目You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and re

题目Given an array of integers and an integer k, find out whether there are two distinct indicesi and j in the array such that nums[i] = nums[j] and theabsolute difference between i and j is at

题目You are given two non-empty linked lists representing two non-negative integers. The most significant digit comes first and each of their nodes contain a single digit. Add the two numbers and

题目Given two strings s and t, write a function to determine ift is an anagram of s.For example,s = "anagram", t = "nagaram", return true.s = "rat", t = "car", return false.Note:You may

题目Given a pattern and a stringstr, find if str follows the same pattern.Here follow means a full match, such that there is a bijection between a letter inpattern and a non-empty word instr

题目Given two arrays, write a function to compute their intersection.Example:Given nums1 = [1, 2, 2, 1],nums2 = [2, 2], return [2].Note:Each element in the result must be unique.The re

题目Given two arrays, write a function to compute their intersection.Example:Given nums1 = [1, 2, 2, 1],nums2 = [2, 2], return [2, 2].Note:Each element in the result should appear as m

题目Given two strings s and t which consist of only lowercase letters.String t is generated by random shuffling strings and then add one more letter at a random position.Find the letter that

题目Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.This is case sensitive, for example "Aa" is not

题目Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the tw

题目Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every elem

题目Given two strings s and t, determine if they are isomorphic.Two strings are isomorphic if the characters in s can be replaced to get t.All occurrences of a character must be replaced wit

题目Description:Count the number of prime numbers less than a non-negative number,n.我的解法（超时）public class Solution { public int countPrimes(int n) { int res = 0; if(n - 1

题目Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.For example:Given num = 38, the process is like:3 + 8 = 11, 1 + 1 = 2. Since2 has only

题目Write a program to check whether a given number is an ugly number.Ugly numbers are positive numbers whose prime factors only include2, 3, 5. For example, 6, 8 are ugly while14 is not ugly

题目Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.For example,Given nums = [0, 1, 3] return 2.我的解法public class So

题目Given a positive integer num, write a function which returns True ifnum is a perfect square else False.Note: Do not use any built-in library function such assqrt.Example 1:Input: 16R

题目Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ...Note:n is positive and will fit within the range of a 32-bit signed integer (n 31).Example 1:Inp

题目Given two non-negative integers num1 andnum2 represented as string, return the sum ofnum1 and num2.Note:The length of both num1 andnum2 is Both num1 andnum2 contains only digits

题目Given a singly linked list, determine if it is a palindrome.Follow up:Could you do it in O(n) time and O(1) space?我的解法/** * Definition for singly-linked list. * public class ListNode {

题目Given a non-empty integer array of sizen, find the minimum number of moves required to make all array elements equal, where a move is incrementingn - 1 elements by 1.Example:Input:[1,2

题目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 t

题目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 integer, replace the number by the sum of the squ

题目Given an array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without usi

题目Given a string s and a non-empty string p, find all the start indices ofp's anagrams in s.Strings consists of lowercase English letters only and the length of both stringss and p will no

题目Related to question Excel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column number.For example:    A -> 1    B -> 2    C -> 3    .

题目Given an integer n, return the number of trailing zeroes inn!.我的解法（超时）public class Solution { public int twoNum = 0; public int fiveNum = 0; public int trailingZeroes

题目Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.我的解法/** * Definition for singly-linked list. *

题目Given a sorted linked list, delete all duplicates such that each element appear onlyonce.For example,Given 1->1->2, return1->2.Given 1->1->2->3->3, return1->2->3.我的解法/** * Defin

题目Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?答案（两指针法）/** * Definition for singly-linked list. * class ListNode { * i

题目Write a program to find the node at which the intersection of two singly linked lists begins.For example, the following two linked lists:A:          a1 → a2                   ↘      

题目Remove all elements from a linked list of integers that have valueval.ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6,val = 6Return: 1 --> 2 --> 3 --> 4 --> 5我的解法/** * Definit

题目Reverse a singly linked list.我的解法（答案解法之一）/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * }

题目Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate numb

题目Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The time complexity must be in O(n).Example 1:Input

题目Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example:    1 -> A    2 -> B    3 -> C    ...    26 -> Z    27 -> AA    28 -> AB 

题目The Hamming distance between two integers is the number of positions at which the corresponding bits are different.Given two integers x andy, calculate the Hamming distance.我的解法publi

题目Implement int sqrt(int x).Compute and return the square root of x.我的解法public class Solution { public int mySqrt(int x) { int s = 1; int e = x; long mid = 0;

题目Given n points in the plane that are all pairwise distinct, a "boomerang" is a tuple of points(i, j, k) such that the distance betweeni and j equals the distance betweeni and k (the order