Leetcode-happy number

Happy number

2015.4.22 12:39

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 and replace the number by the Sum of the squares of its digits, and repeat the process until the number equals 1 (where it would stay), or it loops Endl essly in a cycle which does not include 1. Those numbers for which this process ends in 1 is happy numbers.

Example:19 is a happy number

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

Solution:

Dull.

Accepted Code:

1@@ -0,0+1, $ @@2 //1CE, 1AC, dull3#include <unordered_set>4 using namespacestd;5 6 classSolution {7  Public:8     BOOLIshappy (intN) {9unordered_set<int>us;Tenunordered_set<int>:: iterator it; One          A          while(true) { -             if(n = =1) { -                  Break; the             } -             if(Us.find (n) = =Us.end ()) { - Us.insert (n); -}Else { +                  Break; -             } +n =DSum (n); A         } at         returnn = =1; -     } - Private: -     intDSumintN) { -         ints =0; -         intD; in          while(N >0) { -d = n%Ten; toN/=Ten; +s + = d *D; -         } the          *         returns; $     }Panax Notoginseng};

Leetcode-happy number