How can I multiply really big numbers c++

Question

I have the following code

      int i, a, z;
i = 2343243443;
a = 5464354324324324;
z = i * a;
cout << z << endl;

When these are

Answer 1

You can use queue data structure to find the product of two really big numbers with O(n*m). n and m are the number of digits in a number.