string multiply(string num1, string num2) {
// special cases
if(num1.compare("0")==0 || num2.compare("0")==0) return "0";
// general
int n2=num2.size();
string sum="0";
for(int i=n2-1;i>=0;i--){
string mul = strmul(num1, num2[i]);
sum = strsum(sum, mul, n2-1-i);
}
// return
return sum;
}
void main()
{
char s[100],p[100];
int i,k;
printf("enter the strings of equal length u want to add\n");
scanf("%s%s",s,p);
k=valid(s);
if(k==0){
printf("invalid input");
exit(0);}
k=valid(p);
if(k==0){
printf("invalid input");
exit(0);}
strsum(s,p);
}
void main()
{
char p[100];
int i,k;
printf("enter a number");
scanf("%s",p);
int n=strsum(p);
printf("enter the no.of times\n");
scanf("%d",&k);
if(k==0){
printf("not divisible");
exit(0);}
for(i=0;i<k;i++)
printf("%s",p);
if(n==1)
printf(" divisible by 3");
else
{
if(k%3==0)
printf(" divisible");
else
printf("not divisible");
}
}
