Leetcode OJ 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 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: is a happy number

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

Credits:

Special thanks to @mithmatt and @ts for adding the problem and creating all test cases.

BOOL Ishappy (int n) {int Hash[20];memset (hash,-1, sizeof (hash)), while (1) {int m = 0;while (n) {m + = (n%) * (n% 10); n/= 10;} n = m;if (n = = 1) return true;int p = n% 20;while (hash[p]! =-1) {if (hash[p] = = N) return false;p++;if (p = =) p = 0; }hash[p] = n;}}

Leetcode OJ Happy Number