Write a 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
1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1
For the original question on Leetcode, please see my previous blog happy number.
Solution One:
classSolution { Public: /** * @param n an integer * @return true if the is a happy number or false*/ BOOLIshappy (intN) {Set<int>s; while(n! =1) { intt =0; while(n) {T+ = (n%Ten) * (n%Ten); N/=Ten; } N=T; if(S.count (n)) Break; ElseS.insert (n); } returnn = =1; }};
Solution Two:
classSolution { Public: /** * @param n an integer * @return true if the is a happy number or false*/ BOOLIshappy (intN) { while(n! =1&& n! =4) { intt =0; while(n) {T+ = (n%Ten) * (n%Ten); N/=Ten; } N=T; } returnn = =1; }};
[Lintcode] Happy Number Happiness