happy_number.c

#include<stdio.h>
int main()
{
    int n,q,r,s;
    scanf("%d",&n);
    q=n;
    while(q>0)
    {
        s=0;
        while(q>0)
        {
            r=q%10;
            s=s+r*r;
            q=q/10;
        }
        if(s>9)
        {
            q=s;
        }
    }
    if(s==1||s==7)
    {
        printf("True");
    }
    else
    {
        printf("False");
    }
}