您必须调用 srand()一次，而在 generateWeight()的每个条目上都调用它.由于当今的计算机运行速度很快，并且 time()以秒为单位返回时间，因此大多数情况下会从同一种子重新启动随机数生成器.

You must call srand() once, whereas you call it on every entry into generateWeight(). Since nowadays computers are fast and time() returns the time in seconds, this mostly restarts the random number generator from the same seed.