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…
475. Heaters
Winter is coming! Your first job during the contest is to design a standard heater with fixed warm r…
240. Search a 2D Matrix II
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the follo…
74. Search a 2D Matrix
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the follo…
367. Valid Perfect Square
Given a positive integer num, write a function which returns True if num is a perfect square else Fa…
374. Guess Number Higher or Lower
We are playing the Guess Game. The game is as follows: I pick a number from 1 to n. You have to gues…
278. First Bad Version
You are a product manager and currently leading a team to develop a new product. Unfortunately, the …
69. Sqrt(x)
Implement int sqrt(int x). Compute and return the square root of x. 思路： 这道题不难，用binary search 1-x就行，有…
162. Find Peak Element
A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠…
287. Find the Duplicate Number
Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), pro…