int IsDivisible(int n){
if(n<0){
n=-n;
}
if(n==0 || n==7){
return 1;
}
if(n<10){
return 0;
}
int a;
int b;
a=n/10;
b=(n-a*10);
//printf("\na: %d and b : %d",a,b);
return IsDivisible(a-2*b);
}
int main(){
int n=616;
int result=IsDivisible(n);
if(result){
printf("\n%d is divisible by 7",n);
}else{
printf("\nNot divisible");
}
return 0;
}
void CyclRatFunct::simplifyCRF(){
// cancels factors 1-t^i from the denominator that appear there explicitly
// (and not just as factors of 1-t^j for some j)
SparsePolyRing R=owner(num);
long nd=denom.size();
for(long i=1;i<nd;i++)
{
while(denom[i]>0)
{
if(!IsDivisible(num,1-power(indets(R)[0],i)))
break;
num/=1-power(indets(R)[0],i);
denom[i]--;
}
}
}
