Colors are usually represented by three color gradients (either Red-Green-Blue for 'additive color' or Cyan-Yellow-Magenta for 'subtractive color'). This is because the human eye can differentiate three different clusters of wavelengths, with some overlap, so colors 'between' the main detected colors, such as orange, are actually detected by the green and red receptors, and so appear as a combination of the two.
Why am I mentioning all of this? Because you are using four sets of colors to represent the spectrum, which is unusual. What does the fourth number represent: 'pure' black (as with the 'Key' of the CMYK model? Pure white? Grayscale or 'tone'? An Alpha channel (transparency)? Or do you know at all? All this may be relevant to how you store the numbers, as is Moschops question about the range of the values (because that will tell you how many bits you'll need to represent each color).
this is our revision,but we could not debug it. we just a beginner in c++. would you like to show to us the right way?
using namespace std;
void determinant(int i, int j);
for (int i=0;i<2;i++)
cout<<"Enter the value a1:"<<endl;
cout<<"Enter the value a2:"<<endl;
cout<<"Enter the value b1:"<<endl;
cout<<"Enter the value b2:"<<endl;
cout << "The determinant is"<<det<<endl;