Description The cows are building a roller coaster! They want your help to design as fun a roller coaster as possible, while keeping to the budget. The roller coaster will be built on a long linear stretch of land of length L (1 <= L <= 1,000). The…

很像背包. 这种在一个数轴上进行操作的题常常需要对区间排序. f[i][j]表示距离到i时,花费为j时的权值之和. f[x[i]+l[i]][j+c[i]]=max{f[x[i]][j]+w[i]}(1<=i<=n,0<=j<=B) #include<cstdio> #include<cstring> #include<algorithm> using namespace std; struct Line{int x,l,w,c;}a[10001…

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 又是题解... 设f[i][j]表示费用i长度j得到的最大乐趣 f[i][end[a]]=max{f[i-cost[a][begin[a]]+w[a]} 当f[i-cost[a][begin[a]]可行时 初始化f=-1 f[0][0]=0 #include <cstdio> #include <cstring> #include <cmath> #include…

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…

P2854 [USACO06DEC]牛的过山车Cow Roller Coaster dp 对铁轨按左端点排个序,蓝后就是普通的二维dp了. 设$d[i][j]$为当前位置$i$,成本为$j$的最小花费 $d[i+a[u].w][j+a[u].c]=max(d[i+a[u].w][j+a[u].c],d[i][j]+a[u].f)$ #include<iostream> #include<cstdio> #include<cstring> #include<algo…

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 <…

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: 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)…