经典洗牌算法

# -*-coding:utf-8 -*-
'''
背景
    https://www.jianshu.com/p/4be78c20095e
   在n个不同的数中随机取出不重复的m个数。洗牌算法是将原来的数组进行打散，
   使原数组的某个数在打散后的数组中的每个位置上等概率的出现，刚好可以解决该问题。
洗牌算法
   由抽牌、换牌和插牌衍生出三种洗牌算法，其中抽牌和换牌分别对应
   Fisher-Yates Shuffle和Knuth-Durstenfeld Shhuffle算法。
'''

"""
Author:
   Yao Zhian
Blog:
    https://www.cnblogs.com/shnuxiaoan
Modify:
   2020-01-18
"""
import random

def loadSimpData():
   """
   创建初始牌数组元素
   Parameters:
       无
   Returns:
       dataMat - 牌数据
   """
   num = ['A', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K']
   color = ['♣️', '♦️', '♠️', '♥️']
   num_color = []
   for i in range(len(num)):
      for j in range(len(color)):
         num_color.append(num[i]+color[j])
   return num_color

def shuffle_cards(start_cards, m):
   """
   数据可视化
   Parameters:
       start_cards - 初始牌的数组
       m - 需要的m张不同的牌
   Returns:
      end_cards - 挑选的m张不重复的牌
   """
   length = len(start_cards)
   for i in range(m):
      n = length - i - 1
      k = random.randint(0, n)
      temp = start_cards[k]
      start_cards[k] = start_cards[n]
      start_cards[n] = temp

   end_cards = start_cards[length-m:length]
   return end_cards


if __name__ == '__main__':
   num_color = loadSimpData()
   # print(num_color)
   cards = shuffle_cards(num_color, 17)
   print(cards)