updated makefile and main.cpp
Merge branch 'master' of https://github.com/dougdliu/CSE220_Lab4
Merge branch 'master' of https://github.com/dougdliu/CSE220_Lab4
Merge branch 'master' of https://github.com/dougdliu/CSE220_Lab4
Merge branch 'master' of https://github.com/dougdliu/CSE220_Lab4
include cmath delete std