摘要: import random#如果剩余选择空间个数乘以随机数大于等于剩余选择数,则选择该数,否则跳过def sample(sets, n): res = [] m = t = 0 N = len(sets) for item in sets: u = random.random() if (N-t)*u >= (n-m): t += 1 else: res.append(item) m += 1 t += 1 if m >... 阅读全文
posted @ 2011-06-25 09:39 酱油哥 阅读(186) 评论(0) 推荐(0)