Update 2017-05-31-random-number-generation.md (#692)
Update 2017-05-31-random-number-generation.md (#692)


yixuan/cosx.org,fyears/cosx.org,Lchiffon/cosx.org,hetong007/cosx.org,tomatoiscoding/cosx.org,fyears/cosx.org,cosname/cosx.org,tomatoiscoding/cosx.org,hetong007/cosx.org,hetong007/cosx.org,cosname/cosx.org,Lchiffon/cosx.org,cosname/cosx.org,tomatoiscoding/cosx.org,fyears/cosx.org,yixuan/cosx.org,yixuan/cosx.org,Lchiffon/cosx.org