标签：
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
Credits:
Special thanks to @mithmatt and @ts for adding this problem and creating all test cases.
Subscribe to see which companies asked this question
1 class Solution { 2 public: 3 bool isHappy(int n) { 4 if(n < 0) return false; 5 map<int,int> mp; 6 while(n != 1){ 7 if(mp[n] == 1) return false; 8 mp[n] = 1; 9 n = calculate(n); 10 } 11 return true; 12 } 13 int calculate(int n) 14 { 15 int ret = 0; 16 int temp = 0; 17 while(n){ 18 temp = n % 10; 19 ret += (temp * temp); 20 n /= 10; 21 } 22 return ret; 23 } 24 };
标签：
原文地址：http://www.cnblogs.com/njczy2010/p/5227607.html
