POJ3086 Treats for the Cows(区间DP)】的更多相关文章

题目链接  Treats for the Cows 直接区间DP就好了,用记忆化搜索是很方便的. #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; #define rep(i,a,b) for(int i(a); i <= (b); ++i) #define LL long long + ; LL f[Q]…
Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for…
FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for many reasons…
题目来源:http://poj.org/problem?id=3186 (http://www.fjutacm.com/Problem.jsp?pid=1389) /** 题目意思: 约翰经常给产奶量高的奶牛发特殊津贴,于是很快奶牛们拥有了大笔不知该怎么花的钱. 为此,约翰购置了N(1≤N≤2000)份美味的零食来卖给奶牛们.每天约翰售出一份零食. 当然约翰希望这些零食全部售出后能得到最大的收益.这些零食有以下这些有趣的特性: 零食按照1..N编号,它们被排成一列放在一个很长的盒子里.盒子的两端…
http://www.lydsy.com/JudgeOnline/problem.php?id=1652 dp.. 我们按间隔的时间分状态k,分别为1-n天 那么每对间隔为k的i和j.而我们假设i或者j在间隔时间内最后取.那么在这个间隔时间内最后取的时间就是n-k+1(这个自己想..也就是说,之前在n-(k-1)+1的时间间隔内取过了,现在我们要多了一个时刻,相当于取这个早了一个时间) 然后就是 k为阶段 i为左端点 j=i+k-1为右端点 t=n-k+1为i-j取最后一个的时间 然后转移 f[…
题目链接:http://poj.org/problem?id=3186 题意:第一个数是N,接下来N个数,每次只能从队列的首或者尾取出元素. ans=每次取出的值*出列的序号.求ans的最大值. 样例 : input:5  1 2 1 5 2 output:43 思路:区间dp,用两个指针i和j代表区间,dp[i][j]表示这个区间的最大值. ///最开始想想着每次拿值最小的就好了,因为之前没接触过区间dp,就这样naive的交了,意料之中的WA了. ///找到一个范例 eg:1000001  …
题目链接:http://poj.org/problem?id=3186 题目大意:给出的一系列的数字,可以看成一个双向队列,每次只能从队首或者队尾出队,第n个出队就拿这个数乘以n,最后将和加起来,求最大和. 解题思路:有两种写法: ①这是我一开始想的,从外推到内,设立数组dp[i][j]表示剩下i~j时的最优解,则有状态转移方程: dp[i][j]=dp[i][j]=max(dp[i-1][j]+a[i-1]*(n-(j-i+1)),dp[i][j+1]+a[j+1]*(n-(j+1-i)))…
详见代码 #include <stdio.h> #include <algorithm> #include <string.h> using namespace std; ]; ][];//i到j的最大和是多少 int main() { // freopen("in.txt","r",stdin); int t; while(~scanf("%d",&t)) { ; i<=t; i++) { sc…
传送门 f[i][j][k] 表示 左右两段取到 i .... j 时,取 k 次的最优解 可以优化 k 其实等于 n - j + i 则 f[i][j] = max(f[i + 1][j] + a[i] * (n - j + i), f[i][j - 1] + a[j] * (n - j + i)) 边界 f[i][i] = a[i] * n 递推顺序不好求,所以选择记忆化搜索. ——代码 #include <cstdio> #include <iostream> ; int n…
第一眼感觉是贪心,,果断WA.然后又设计了一个两个方向的dp方法,虽然觉得有点不对,但是过了样例,交了一发,还是WA,不知道为什么不对= =,感觉是dp的挺有道理的,,代码如下(WA的): #include <stdio.h> #include <algorithm> #include <string.h> using namespace std; + ; int a[N]; int dp[N][N]; int n; int getDay(int i,int j) {…
P2858 [USACO06FEB]奶牛零食Treats for the Cows区间dp,级像矩阵取数, f[i][i+l]=max(f[i+1][i+l]+a[i]*(m-l),f[i][i+l-1]+a[i+l]*(m-l)); #include<iostream> #include<cstdio> #include<queue> #include<algorithm> #include<cmath> #include<ctime&g…
P2858 [USACO06FEB]奶牛零食Treats for the Cows 区间dp 设$f[l][r]$为取区间$[l,r]$的最优解,蓝后倒着推 $f[l][r]=max(f[l+1][r]+a[l]*p,f[l][r-1]+a[r]*p)$ #include<iostream> #include<cstdio> #include<cstring> using namespace std; int max(int a,int b){return a>b…
Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for…
http://poj.org/problem?id=3186   Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time…
[BZOJ 1652][USACO 06FEB]Treats for the Cows Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given…
Treats for the Cows Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7949   Accepted: 4217 Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per da…
题目描述 FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for many re…
Treats for the Cows 先搬中文 Descriptions: 给你n个数字v(1),v(2),...,v(n-1),v(n),每次你可以取出最左端的数字或者取出最右端的数字,一共取n次取完.假设你第i次取的数字是x,你可以获得i*x的价值.你需要规划取数顺序,使获得的总价值之和最大. Input 第一行一个数字n(1<=n<=2000). 下面n行每行一个数字v(i).(1<=v(i)<=1000) Output 输出一个数字,表示最大总价值和. Sample In…
Description 约翰经常给产奶量高的奶牛发特殊津贴,于是很快奶牛们拥有了大笔不知该怎么花的钱.为此,约翰购置了N(1≤N≤2000)份美味的零食来卖给奶牛们.每天约翰售出一份零食.当然约翰希望这些零食全部售出后能得到最大的收益.这些零食有以下这些有趣的特性: •零食按照1..N编号,它们被排成一列放在一个很长的盒子里.盒子的两端都有开口,约翰每 天可以从盒子的任一端取出最外面的一个. •与美酒与好吃的奶酪相似,这些零食储存得越久就越好吃.当然,这样约翰就可以把它们卖出更高的价钱. •每份…
题目传送门 做完A Game以后找道区间dp练练手...结果这题没写出来(哭). 和A Game一样的性质,从两边取,但是竟然还有天数,鉴于之前做dp经常在状态中少保存一些东西,所以这次精心设计了状态(不对的). 开始的naive想法:设f[i][j][0/1]为把第1~i / i~n的零食兜售完所得的最多钱,然后我们就会发现这个状态十分难转移. 水题还看了题解. 十分朴素的区间dp,和我在能量项链总结的如出一辙. 本题突破口:可以直接通过区间来得出当前是第几天!! Code #include<…
裸的区间dp,设f[i][j]为区间(i,j)的答案,转移是f[i][j]=max(f[i+1][j]+a[i](n-j+i),f[i][j-1]+a[j]*(n-j+i)); #include<iostream> #include<cstdio> using namespace std; const int N=2005; int n,a[N],f[N][N]; int main() { scanf("%d",&n); for(int i=1;i<…
题目链接:http://poj.org/problem?id=3186 Treats for the Cows Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6548   Accepted: 3446 Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amount…
dp( L , R ) = max( dp( L + 1 , R ) + V_L * ( n - R + L ) , dp( L , R - 1 ) + V_R * ( n - R + L ) ) 边界 : dp( i , i ) = V[ i ] * n -------------------------------------------------------------------------------------------- #include<cstdio> #include&l…
Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for…
题意:给一个数组v,每次可以取前面的或者后面的,第k次取的v[i]价值为v[i]*k,问总价值最大是多少. 区间dp. 区间dp可以不枚举len  直接枚举i和j即可  见代码 #include <iostream> #include <cstdio> #include <algorithm> #include <cstring> using namespace std; #define maxx 2010 int dp[maxx][maxx]; int m…
题目 1652: [Usaco2006 Feb]Treats for the Cows Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 234  Solved: 185[Submit][Status] Description FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ se…
一.区间DP解题时常见思路 如果题目中答案满足: 大的区间的答案可以由小的区间答案组合或加减得到 大的范围可以由小的范围代表 数据范围较小 我们这时可以考虑采用区间DP来解决. 那么常见的解法有两种: 1.用小的区间组合松弛大的区间,即枚举断点,分割区间,与答案取优. 2.用比当前区间略小的区间转移,用一些区间边界代表转移用的性质,通过常数的加减得到答案. 二.相关题目 下面我们通过一些题目来体验两中解法,笔者认为的难度用*的个数表示. 解法1的题目: 1.***[BZOJ 4350]括号序列再…
[USACO06FEB]奶牛零食Treats for the Cows 思路: 区间DP: 代码: #include <bits/stdc++.h> using namespace std; #define maxn 2005 #define ll long long ll n,ai[maxn],dp[maxn][maxn],sum[maxn]; inline void in(ll &now) { ; ')Cget=getchar(); ') { now=now*+Cget-'; Cg…
题目描述 FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for many re…
SP740 TRT - Treats for the Cows 题目描述 FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The tr…