645. Set Mismatch

645. Set Mismatch

The set S originally contains numbers from 1 to n. But unfortunately, due to the data error, one of …

202. Happy Number

202. Happy Number

Write an algorithm to determine if a number is “happy”. A happy number is a number defin…

258. Add Digits

258. Add Digits

Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.…

231. Power of Two

231. Power of Two

Given an integer, write a function to determine if it is a power of two. class Solution { public boo…

263. Ugly Number

263. Ugly Number

Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers…

507. Perfect Number

507. Perfect Number

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divi…

172. Factorial Trailing Zeroes

172. Factorial Trailing Zeroes

Given an integer n, return the number of trailing zeroes in n!. Note: Your solution should be in log…

633. Sum of Square Numbers

633. Sum of Square Numbers

Given a non-negative integer c, your task is to decide whether there’re two integers a and b s…

598. Range Addition II

598. Range Addition II

Given an m * n matrix M initialized with all 0‘s and several update operations. Operations are…

326. Power of Three

326. Power of Three

Given an integer, write a function to determine if it is a power of three. Follow up: Could you do i…

返回顶部