One Billion Dollars, Guaranteed
Just implement this function for all values:
float GetStockPrice( char* sym, int date );
Some things are impossible, and it's good to recognize them. The tricky part is most impossible ideas are not as clearly defined at the function level.
For example, look at this figure:
(source)
Now in your mind rotate it on the vertical axis. Not too hard was it?
Though the figure can't exist, it's still possible to think it does. The problem is your brain isn't a computer and it fudges some things that otherwise would make the idea impossible. It also can't see things from all angles, so though the figure above looks correct from that specific perspective, in reality it may not be from another.
The same thing applies to software and ideas. Some things customers and program managers want just can't be implemented. Some things are seen as being obvious and totally feasible from one perspective doesn't work from another customer's perspective. The ideas for the perfect behavior for a program will always conflict. That's why it takes engineering to accomplish something. To turn a nebulous, outlandish idea into something working and functioning in the real world.
Can I write a function that accurately predicts stock for all future dates? No. Can I write a function that looks up a stock price on a given day in the past? Sure. It's not exactly what the customer wanted, but it is useful and provides other people with a platform to build their complete solutions on.
Don't embark on solving everyone's wish to make the program do exactly what they want, instead provide a great product that enables people to do exactly what they want.
