JayXu's Blog

Write an algorithm to determine if a number n 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 squares of its digits, and repeat the process until the number e

Given a non-empty 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 usin...

You are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed based on the...

Day1. 输入一个链表，输出该链表中倒数第k个结点。 代码 public class ListNode { int val; ListNode next = null; ListNode(int val) { this.val = val; } } /** * 先搞一个stack，把所有的listNode都放进去，看看stack的大小的1/2是...