随笔分类 -  数论——容斥原理

[USACO12FEB]附近的牛Nearby Cows
摘要：题目描述 Farmer John has noticed that his cows often move between nearby fields. Taking this into account, he wants to plant enough grass in each of his f 阅读全文
posted @ 2017-09-14 15:41 J_william 阅读(305) 评论(0) 推荐(0)
[SCOI2010]幸运数字
摘要：题目背景 四川NOI省选2010 题目描述 在中国，很多人都把6和8视为是幸运数字！lxhgww也这样认为，于是他定义自己的“幸运号码”是十进制表示中只包含数字6和8的那些号码，比如68，666，888都是“幸运号码”！但是这种“幸运号码”总是太少了，比如在[1,100]的区间内就只有6个（6，8， 阅读全文
posted @ 2017-03-26 17:54 J_william 阅读(627) 评论(0) 推荐(0)