zshouyi的博客

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.这道题应该注意只要是在一条直线上就算。第一反应是用HashMap来存斜率，但是如果double精确到小数点后好多位之后就趋于相等，key值就相等了，所以一般不要用double作key。这里可以用

Given a positive integer n and you can do operations as follow:If n is even, replace n with n/2.If n is odd, you can replace n with either n + 1 or n - 1.What is the minimum number o

Given a non-empty string containing an out-of-order English representation of digits 0-9, output the digits in ascending order.Note:Input contains only lowercase English letters.Input is g

You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactly z litres using these two

A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.For example, these are arithmetic seque

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

Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x n.Example:Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x [11,22,33,44,

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.Example1:a = 2b = [3]Result: 8Example

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 following sequence (ie, for n = 3):"123""132""213""231""3

Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies: Si % Sj = 0 or Sj % Si = 0.If there are multiple solution

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, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the first 

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Find all strobogrammatic numbers that are of length = n. For example,Given n = 2, re

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 list primes of size k. For example, [1, 2, 4, 7, 8, 13,

Given a sorted array of integers nums and integer values a, b and c. Apply a function of the form f(x) = ax2 + bx + c to each element x in the array. The returned array must be in sorted order.

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[2] metres to the south, x[3] metres to the east and s

Given a list of positive integers, the adjacent integers will perform the float division. For example, [2,3,4] -> 2 / 3 / 4.However, you can add any number of parenthesis at any position to change

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an integer n, write a function that returns true when it is a per

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up t

Note: This is a companion problem to the System Design problem: Design TinyURL.TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl an

Given two strings representing two complex numbers.You need to return a string representing their multiplication. Note i2 = -1 according to the definition.Example 1:Input: "1+1i", "1+1i"O

Given a list of points that form a polygon when joined sequentially, find if this polygon is convex (Convex polygon definition).Note:There are at least 3 and at most 10,000 points.Coordinate

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 every third bulb (turning on if it's off or turning off

A group of two or more people wants to meet and minimize the total travel distance. You are given a 2D grid of values 0 or 1, where each 1 marks the home of someone in the group. The distance is calcu

Given a non-empty integer array, find the minimum number of moves required to make all array elements equal, where a move is incrementing a selected element by 1 or decrementing a selected element by

Given n points on a 2D plane, find if there is such a line parallel to y-axis that reflect the given points.Example 1:Given points = [[1,1],[-1,1]], return true.Example 2:Given poi

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 maximum product you can get.For example, given n = 2, ret

Given an array of integers A and let n to be its length.Assume Bk to be an array obtained by rotating the array A k positions clock-wise, we define a "rotation function" F on A as follow:

Given a non-empty integer array of size n, find the minimum number of moves required to make all array elements equal, where a move is incrementing n - 1 elements by 1.Example:Input:[1,2,3]Ou

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 Credits

Given an integer, write a function to determine if it is a power of two.Credits:Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.判断一个数是不是2的次幂，从bit入手。如

Find the total area covered by two rectilinear rectangles in a 2D plane.Each rectangle is defined by its bottom left corner and top right corner as shown in the figure.Assume that the tota

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?Credits:Special thanks to @dietpepsi for adding this

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Write a function to determine if a number is strobogrammatic. The number is represented as

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 is at the head of the list.中文：给出一个由整型数组表示的非负数字，将这

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. For example, 6, 8 are ugly while 14 is not ugly si

Description:Count the number of prime numbers less than a non-negative number, n.Credits:Special thanks to @mithmatt for adding this problem and creating all test cases.统计小于n 的质数的个数。创建大小n

Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2.Note:The length of both num1 and num2 is Both num1 and num2 contains only digits 0-9.

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:Inpu

You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins.Given n, find the total number of full staircase rows that can be formed.

Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.1、让divisor一直乘22、如果divisor>dividend，则用dividend - 上一个divisor3、余下的数继续重复1，2步这里有两种情