SRM473 Div2 Easy(250) OnTheFarmDivTwo

OnTheFarmDivTwo

#include <vector>

using namespace std;

class OnTheFarmDivTwo
{
public:
    vector <int> animals( int heads, int legs );
};

vector <int> OnTheFarmDivTwo::animals( int heads, int legs )
{
    vector<int> ans;
    ans.push_back( 2*heads - legs/2 );
    ans.push_back( legs/2 - heads );

    if ( 0 <= ans[0]  &&  0 <= ans[1]  &&
         ans[0] + ans[1] == heads  &&
         2*ans[0] + 4*ans[1] == legs )
        return ans;
    else
        return vector<int>();
}