Happy number
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 = 828^2 + 2^2 = 686^2 + 8^2 = 1001^2 + 0^2 + 0^2 = 1
Public classSolution {/** * @paramn an integer *@returntrue if this is a happy number or false*/ Boolean[] visited=New Boolean[100]; Public BooleanIshappy (intN) {if(n<visited.length&&Visited[n])return false; if(n<visited.length) {Visited[n]=true; } intSum=0; while(N > 0) { intd = n% 10; Sum+ = d *D; N/= 10; } if(Sum = = 1) return true; returnishappy (sum); }}
Lintcode Easy Happy Number