vc开发的很实用的浮动时钟，可以实现透明化，可以放到桌面上代替系统时钟！-vc practical development of the floating clock, can achieve a transparent, decentralized desktop replacement system clock!

包括了Clock,，FIFO，LRU，OPT，随机替换五种页面置换算法-Including the Clock, the FIFO, LRU, OPT, randomly replace the five page replacement algorithm