a863. 3. Happy Numbers -- HP CodeWars2010 | From: [111.254.212.6] | 發表日期 : 2014-10-06 22:55

#include<cstdio>

int main(){

    int n;

   while(~scanf("%d",&n)){

   printf("%d is ",n);

    int sum=0;

    bool happy=true;

   while(n!=1)

{

   while(n){

    sum+=(n%10)*(n%10);

    n/=10;

    }

   n=sum,sum=0;   

   if(n==4){//上網查到說"只要是unhappy"就會進入4的循環

    happy=false;

    break;        

    } 

}

if(happy) printf("a happy number\n");

else printf("an unhappy number\n");

  

}}