摘要: 题意: n头牛,a种食物,b种饮料,每种食物和饮料只有一份,每头牛有一些喜欢的食物和饮料,若牛得到了一种自己喜欢的食物和饮料就会得到满足,求最多能有多少牛可以得到满足 题解: 源点向食物连边,食物向牛连边,牛再向饮料连边,跑一遍最大流,这样是不对的 因为每头牛只能分配一种食物和饮料,上述那样连边跑最 阅读全文
posted @ 2017-10-12 14:12 HLX_Y 阅读(183) 评论(0) 推荐(0) 编辑
摘要: 题意: "原题链接" 题解: 建图:源点向所有正权点连正权权值的边,负权点向汇点连负权的绝对值的边,正权点与负权点之间的边为inf 最大权闭合子图=正权和 最小割 include include include include include include include define ll lo 阅读全文
posted @ 2017-10-12 10:54 HLX_Y 阅读(145) 评论(0) 推荐(0) 编辑
摘要: 题意: "原题链接" 题解: 最小路径覆盖指的是划分出n条路径,每条路径没有交点,要求覆盖所有结点,求n的最小值 结论:最小路径覆盖=n 二分图最大匹配 最大流跑一遍二分图匹配即可 include include include include include include include def 阅读全文
posted @ 2017-10-12 10:49 HLX_Y 阅读(128) 评论(0) 推荐(0) 编辑
摘要: 题意: 二分图多重匹配 问你匹配完之后,到汇点是否满流 题解: 最大流 include include include include include include include define ll long long define N 100010 using namespace std; i 阅读全文
posted @ 2017-10-12 00:12 HLX_Y 阅读(149) 评论(0) 推荐(0) 编辑