文件datas中包含某人浏览商品的记录,每行格式如下:
https://item.jd.com/3498333.html
其中,数字就是商品的编号。编写一个程序统计各商品的浏览次数。
使用下面数据
datas = [
'https://item.jd.com/3498333.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/2385876.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/3498333.html'
]
2、约瑟夫问题是个有名的问题:N个人围成一圈,从第一个开始报数,第M个将被杀掉,最后剩下一个,其余人都将被杀掉。例如N=6,M=5,被杀掉的顺序是:5,4,6,2,3。编写程序求解该问题。
from collections import Counter
datas = [
'https://item.jd.com/3498333.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/2385876.html',
'https://item.jd.com/3498333.html',
'https://item.jd.com/5364377.html',
'https://item.jd.com/3498333.html'
]
##统计列表中数据出现的次数
res = dict(Counter(datas))
print(res)
#{'https://item.jd.com/3498333.html': 6, 'https://item.jd.com/5364377.html': 3, 'https://item.jd.com/2385876.html': 1}