直接从每个奶牛所在的farm dfs , 然后算一下.. ---------------------------------------------------------------------------------------- #include<cstdio> #include<algorithm> #include<cstring> #include<iostream> #include<vector>   #define rep( i…
1648: [Usaco2006 Dec]Cow Picnic 奶牛野餐 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 554  Solved: 346[Submit][Status][Discuss] Description The cows are having a picnic! Each of Farmer John's K (1 <= K <= 100) cows is grazing in one of N (1 <= N <…
Description The cows are having a picnic! Each of Farmer John's K (1 <= K <= 100) cows is grazing in one of N (1 <= N <= 1,000) pastures, conveniently numbered 1...N. The pastures are connected by M (1 <= M <= 10,000) one-way paths (no p…
从每个奶牛所在草场dfs,把沿途dfs到的草场的con都+1,最后符合条件的草场就是con==k的,扫一遍统计一下即可 #include<iostream> #include<cstdio> using namespace std; const int K=105,N=1005; int k,n,m,p[K],h[N],cnt,c[N],v[N],ti,ans; struct qwe { int ne,to; }e[N*10]; int read() { int r=0,f=1;…
1648: [Usaco2006 Dec]Cow Picnic 奶牛野餐 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 432  Solved: 270[Submit][Status] Description The cows are having a picnic! Each of Farmer John's K (1 <= K <= 100) cows is grazing in one of N (1 <= N <= 1,000)…
http://www.lydsy.com/JudgeOnline/problem.php?id=1648 水题.. dfs记录能到达的就行了.. #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm> #include <queue> using name…
Description The cows are having a picnic! Each of Farmer John's K (1 <= K <= 100) cows is grazing in one of N (1 <= N <= 1,000) pastures, conveniently numbered 1...N. The pastures are connected by M (1 <= M <= 10,000) one-way paths (no p…
有点类似背包 , 就是那样子搞... ------------------------------------------------------------------------------------ #include<cstdio> #include<cstring> #include<algorithm> #include<iostream> #define rep( i , n ) for( int i = 0 ;  i < n ; ++i…
http://www.lydsy.com/JudgeOnline/problem.php?id=1649 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 743  Solved: 370[Submit][Status][Discuss] Description The cows are building a roller coaster! They want your help to design as fun a roller coaster as…
DAG上的dp 因为本身升序就是拓扑序,所以建出图来直接从1到ndp即可,设f[i][j]为到i花费了j #include<iostream> #include<cstdio> using namespace std; const int N=1005,inf=1e9+7; int n,m,b,h[N],cnt,f[N][N],ans=-inf; struct qwe { int ne,to,va,c; }e[N*10]; int read() { int r=0,f=1; cha…