题目链接在这里 此题DP.用一个前缀和一样的东西,把载i个奶牛的时间求出来,然后DP代码如下: ;i<=n;++i){ f[i]=que[i]; ;j<i;++j) f[i]=min(f[i],f[j]+que[i-j]); } 这句话的意思是说,先载i头奶牛,然后从载0头到载i-1头寻找,看有没有更优解.如果有,那么更新. 最后输出的时候输出DP[n]-m,因为最后FJ是不用再回对岸的 放上代码 #include<cstdio> #include<cstdlib> #…

P2904 [USACO08MAR]跨河River Crossing 显然的dp 设$f[i]$表示运走$i$头奶牛,木筏停在未过河奶牛一侧所用的最小代价 $s[i]$表示一次运$i$头奶牛到对面的代价 我们枚举上次运走了$j$头,显然$f[i]=min(f[i],f[i-j]+s[j]+s[0])$(注意自己要划回来) 最后不用划回来,减去一个$s[0]$即可 end. #include<iostream> #include<cstdio> #include<cstring…

题目描述 Farmer John is herding his N cows (1 <= N <= 2,500) across the expanses of his farm when he finds himself blocked by a river. A single raft is available for transportation. FJ knows that he must ride on the raft for all crossings and that that…

题目描述 Farmer John is herding his N cows (1 <= N <= 2,500) across the expanses of his farm when he finds himself blocked by a river. A single raft is available for transportation. FJ knows that he must ride on the raft for all crossings and that that…

https://www.luogu.org/problem/show?pid=2904 题目描述 Farmer John is herding his N cows (1 <= N <= 2,500) across the expanses of his farm when he finds himself blocked by a river. A single raft is available for transportation. FJ knows that he must ride…

题目描述 Farmer John is herding his N cows (1 <= N <= 2,500) across the expanses of his farm when he finds himself blocked by a river. A single raft is available for transportation. FJ knows that he must ride on the raft for all crossings and that that…

题目 动规方程 f[i]=min(f[i],f[i−j]+sum) 我们默认为新加一头牛,自占一条船.想象一下,它不断招呼前面的牛,邀请它们坐自己这条船,当且仅当所需总时间更短时,前一头奶牛会接受邀请,最多邀请前面的所有奶牛一起坐这条船. #include<iostream> #include<cstring> #include<cstdio> using namespace std; ; int n,m,mt[maxn],f[maxn]; int main(){ sc…

传送门 f[i] 表示送前 i 头牛过去再回来的最短时间 f[i] = min(f[i], f[j] + sum[i - j] + m) (0 <= j < i) ——代码 #include <cstdio> #include <iostream> , INF = ; int n, m; int sum[MAXN], f[MAXN]; inline long long read() { , f = ; char ch = getchar(); ; ) + (x <…

题目背景 loidc,LOI中的传说级哲♂学家,曾经创造一天内入坑maxlongint个弃坑0x7fffffff个的神奇纪录.目前,loidc最喜欢的游戏就是地下城与勇♂士. 题目描述 Loidc是一个勤奋的孩子. 他每天都会勤奋的搬砖刷疲劳,每天都会期待着各种BOSS给他爆点什么神奇的东西(例如魔剑..),但是每次刷远古总会坑到连门票钱也赚不回来. 最近loidc新技能get√ 他每天都会朗诵一遍线段树,将自己升级为”Deep Dark Fantasy”模式(其实是每天去给腾讯爹送钱)下才去搬…

[luogu]P1070 道路游戏 题目描述小新正在玩一个简单的电脑游戏.游戏中有一条环形马路,马路上有 n 个机器人工厂,两个相邻机器人工厂之间由一小段马路连接.小新以某个机器人工厂为起点,按顺时针顺序依次将这 n 个机器人工厂编号为1~n,因为马路是环形的,所以第 n 个机器人工厂和第 1 个机器人工厂是由一段马路连接在一起的.小新将连接机器人工厂的这 n 段马路也编号为 1~n,并规定第 i 段马路连接第 i 个机器人工厂和第 i+1 个机器人工厂(1≤i≤n-1),第 n 段马路连接第…