Its a simple implementation of Russians Peasant multiplication algorithm.

rusmulti.cpp

#include<iostream>
using namespace std;

int main()
{
  int a,b,c=0;
  cin >> a >> b;
  while(a)
  {
        if(a&1)
          c += b;
        a>>=1;
        b<<=1;
  }
  cout<<m<<endl;
  return 0;
}