I'm struggling at the starting point of breakout in pset3. I've downloaded the breakout set using wget http://cdn.c50.net/2014/fall/lectures/4/m/scr4m.zip according to the CS50 2015 instruction. It was downloaded allright to my PC and I could upzip it. Then I did 'cd src4m', and found all of the programs listed in the breaking out from bounce.c to window.c. Then tried to compile window by keying in 'make window' without any modification to the original window.c.
It will be greatly appreciated if anyone could tell me how to solve this problem. As far as I searched the solution in this StackExchange, I did not see any clue to my problem.