此头文件包含一个产生（0，1）的随机数的函数：random（），种子是系统当前时间，每次产生的伪随机数序列不一样。可直接调用此函数。-This header file contains a generation (0,1) random number function: random (), seed is the system current time, each produced by pseudo-random number sequences are different. Call this function directly.