James Pan

原题网址：https://leetcode.com/problems/power-of-three/Given an integer, write a function to determine if it is a power of three.Follow up:Could you do it without using any loop / recursion?方

原题网址：https://leetcode.com/problems/max-points-on-a-line/Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.方法一：逐点比较斜率。/** * Definition for a

原题网址：https://leetcode.com/problems/permutation-sequence/The set [1,2,3,…,n] contains a total of n! unique permutations.By listing and labeling all of the permutations in order,We get the

原题网址：https://leetcode.com/problems/water-and-jug-problem/You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine wheth

原题网址：https://leetcode.com/problems/plus-one/Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit i

原题网址：https://leetcode.com/problems/add-binary/Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".方法一：使用字符串来表示。public class So

原题网址：https://leetcode.com/problems/sqrtx/Implement int sqrt(int x).Compute and return the square root of x.方法一：二分法。public class Solution { public int mySqrt(int x) { int i=0,

原题网址：https://leetcode.com/problems/self-crossing/You are given an array x of n positive numbers. You start at point (0,0) and moves x[0] metres to the north, then x[1] metres to the west, x[

原题网址：https://leetcode.com/problems/count-numbers-with-unique-digits/Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x n.Example:Given n = 2, return 91. (

原题网址：https://leetcode.com/problems/ugly-number-ii/Write a program to find the n-th ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 1, 2

原题网址：https://leetcode.com/problems/super-pow/Your task is to calculate ab mod 1337 where a is a positive integer and b is an extremely large positive integer given in the form of an array.Exam

原题网址：https://leetcode.com/problems/integer-break/Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximu

原题网址：https://leetcode.com/problems/patching-array/Given a sorted positive integer array nums and an integer n, add/patch elements to the array such that any number in range [1, n] inclusive ca

原题网址：https://leetcode.com/problems/largest-divisible-subset/Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfie

原题网址：https://leetcode.com/problems/super-ugly-number/Write a program to find the nth super ugly number.Super ugly numbers are positive numbers whose all prime factors are in the given prime

原题网址：https://leetcode.com/problems/convex-polygon/Given a list of points that form a polygon when joined sequentially, find if this polygon is convex (Convex polygon definition).Note:T

原题网址：https://leetcode.com/problems/divide-two-integers/Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.方法一：使用长整数处理溢出问题。publi

原题网址：https://leetcode.com/problems/palindrome-number/Determine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negative integers

原题网址：https://leetcode.com/problems/power-of-two/Given an integer, write a function to determine if it is a power of two.思路：数字n是2的整数次幂，当且仅当n的二进制表示有且只有一个1。public class Solution { public boo

原题网址：https://leetcode.com/problems/ugly-number/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. F

原题网址：https://leetcode.com/problems/find-the-celebrity/Suppose you are at a party with n people (labeled from 0 to n - 1) and among them, there may exist one celebrity. The definition of a cele

原题网址：https://leetcode.com/problems/perfect-squares/Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n.For example, g

原题网址：https://leetcode.com/problems/factor-combinations/Numbers can be regarded as product of its factors. For example,8 = 2 x 2 x 2; = 2 x 4.Write a function that takes an integer n and

原题网址：https://leetcode.com/problems/nim-game/You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 ston

原题网址：https://leetcode.com/problems/add-digits/Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.For example:Given num = 38, the proces

原题网址：https://leetcode.com/problems/intersection-of-two-arrays-ii/Given two arrays, write a function to compute their intersection.Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], retu

原题网址：https://leetcode.com/problems/factorial-trailing-zeroes/Given an integer n, return the number of trailing zeroes in n!.Note: Your solution should be in logarithmic time complexity.方法：

原题网址：https://leetcode.com/problems/excel-sheet-column-title/Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B

原题网址：https://leetcode.com/problems/fraction-to-recurring-decimal/Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.If the frac

原题网址：https://leetcode.com/problems/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

原题网址：https://leetcode.com/problems/sparse-matrix-multiplication/Given two sparse matrices A and B, return the result of AB.You may assume that A's column number is equal to B's row number.

原题网址：https://leetcode.com/problems/count-primes/Description:Count the number of prime numbers less than a non-negative number, n.Credits:Special thanks to @mithmatt for adding this pro

原题网址：https://leetcode.com/problems/bulb-switcher/There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle e

原题网址：342. Power of Four 342. Power of Four 342. Power of Four 342. Power of FourGiven an integer (signed 32 bits), write a function to check whether it is a power of 4.Example:Given num =

原题网址：https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/Given a non-empty integer array, find the minimum number of moves required to make all array elements equal, where a m