uva 10591 - Happy Number

Problem C
Happy Number
Time Limit
1 Second
 
Let the sum of the square of the digits of a positive integer S0 be represented by S1. In a similar way, let the sum of the squares of the digits of S1 be represented by S2 and so on. If Si = 1 for some i ³ 1, then the original integer S0 is said to be Happy number. A number, which is not happy, is called Unhappy number. For example 7 is a Happy number since 7 -> 49 -> 97 -> 130 -> 10 -> 1 and 4 is an Unhappy number since 4 -> 16 -> 37 -> 58 -> 89 -> 145 -> 42 -> 20 -> 4.
 
Input
The input consists of several test cases, the number of which you are given in the first line of the input. Each test case consists of one line containing a single positive integer N smaller than 109.
 
Output
For each test case, you must print one of the following messages:
 
Case #p: N is a Happy number.
Case #p: N is an Unhappy number.
 
Here p stands for the case number (starting from 1). You should print the first message if the number N is a happy number. Otherwise, print the second line.
 
Sample Input
Output for Sample Input
3 7 4 13
Case #1: 7 is a Happy number. Case #2: 4 is an Unhappy number. Case #3: 13 is a Happy number.
 
Problemsetter: Mohammed Shamsul Alam
International Islamic University Chittagong
Special thanks to Muhammad Abul Hasan
99999999->81*8
표기수 그룹 판정 순환 최대 9*9*8

#include<stdio.h>
#include<string.h>
int sort(int x)
{int y=0;
 while (x>0)
 {y=y+(x%10)*(x%10);
  x=x/10;
 }
 return y;
}
int main()
{int n,m,t,i,visit[1000];
 scanf("%d",&t);
 for (i=1;i<=t;i++)
 {scanf("%d",&n);
  memset(visit,0,sizeof(visit));
  m=n;
  while (n)
  {m=sort(m);
   if (m==1) {printf("Case #%d: %d is a Happy number.
",i,n);break;}
   if (visit[m]) {printf("Case #%d: %d is an Unhappy number.
",i,n);break;}
   visit[m]=1;
  }
 }
 return 0;
}