力扣面试150 快乐数 循环链表找环 链表抽象 哈希

Problem: 202. 快乐数

👩‍🏫 参考题解

Code

public class Solution {public int squareSum(int n) {int sum = 0;while(n > 0){int digit = n % 10;sum += digit * digit;n /= 10;}return sum;}public boolean isHappy(int n) {int slow = n, fast = squareSum(n);while (slow != fast){slow = squareSum(slow);fast = squareSum(squareSum(fast));};return slow == 1;}
}