这个题主要是转化为最小割的思路不好想到. 大意:给你一个大的正方形,有的点黑,有的点白,要把黑染白,你每次可以选一个矩形染色,代价是min(长,宽),问最小代价. 思路:对于一个要染色的块来说,他要被行覆盖或列覆盖(选小的),就是min(占行数,占列数).然后可以这样建网络流:源点->行结点(容量是占行数)->无穷大的边->列结点(容量是占列数)->汇点,然后跑最小割(最大流). #include<bits/stdc++.h> #define M 405 using n…
You are given an undirected graph G(V, E). Each vertex has a mark which is an integer from the range [0..231 – 1]. Different vertexes may have the same mark. For an edge (u, v), we define Cost(u, v) = mark[u] xor mark[v]. Now we know the marks of som…
Time Limit: 5 Seconds Memory Limit: 32768 KB Special Judge Network of Byteland consists of n servers, connected by m optical cables. Each cable connects two servers and can transmit data in both directions. Two servers of the network are especially i…