Lortnok Lortnok - 3 months ago 9
C++ Question

If treble product of first 2 digits

I am writing a program that should be able to calculate the product of first n-1 digits.

Note: If treble first 2 digits.

The code is working when 4 digits entered , example : 1234 , product is 6 . Cant figure out the treble part

So far I tried this, but no solution:

using namespace std;
int main()
{

int n , sum = 0, s,d,k,w, product ;
cout <<"Enter number: " << endl;
cin >> n;

if ((n>1) && (n<10000)) {
{
s= n/10;
d = n/100%10; // 2.
k = n/1000%100%10; //1.
w = n/10%10; //3.
//1234
product = w*d*k;


if ((n>1) && (n<1000)) {
s = n/10;
d = n/100%10; // 2.
k = n/1000%100%10; //1.
w = n/10%10; //3.

product = k*d;

}
cout <<"Sum of digits inp numb is : " << d+k+w << " and product is : " << product << endl;

cout << "w: " << w << " k: " << k << " d: " << d << " s: " << s << endl;

}
}
return 0;
}

Answer
 if ((n>1) && (n<1000)) {
       s = n/10;
    d = n/100%10; // 2.
    k = n/1000%100%10; //1.
    w = n/10%10; //3.

    product = k*d;

}

This part should be your "treble" part. This line is the issue:

product = k*d;.

If n < 1000, then k becomes 0%100%10 which is 0. Thus your product is 0. I think your intention was:

product = w*d;

For the general solution, repeatedly divide and take the running product of the modulus. Like this:

n = n/10;
product = 1;
while (n > 0){
    product = product * (n%10);
    n = n/10;
}