leetcode-202-Happy Number _leetcode

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【leetcode-202-Happy Number】 Happy Number

Write an algorithm to determine if a number 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 equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.
Example: 19 is a happy number

12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

直接模拟。

class Solution { public: bool isHappy(int n) { if (n == 1) return true; int m ; map< int,int> a; while (n != 1) { if (a[n] == 1) break; a[n] = 1; m = 0 ; while (n) { m += (n%10) * (n%10) ; n = n/10 ; } n = m ; if (n == 1) return true; } return false; } };