P2983 [USACO10FEB]购买巧克力Chocolate Buying 题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of choc…

P2983 [USACO10FEB]购买巧克力Chocolate Buying 题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of choc…

购买巧克力Chocolate Buying 乍一看以为是背包,然后交了一个感觉没错的背包上去. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; //Mystery_Sky // #define M 10000000 #define ll long long ll f[M]; ll p[M], num[M], s…

题目传送门 继续dp刷题计划,看到这道题,第一眼感觉不就是显然的完全背包嘛.把背包打完要开始填充数组大小的时候成为了mengbier,发现数据极大,达到了1e18.显然这不是一道平凡的背包题目. 于是看了题解.wtf?这题是贪心??? emmm冷静分析:首先我们比较背包模型和这个模型,背包花费这一定的体积,那些价值一定会获得.而这个模型中,我们每花费一定的钱(体积),却只能满足一只奶牛.这是本题的关键. 那么就很难继续满足完全背包的性质了. 真想用背包?看到讨论里有人说如果这题写背包,那也得是多…

题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of chocolate has price P_i (1 <= P_i <= 1…

题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of chocolate has price P_i (1 <= P_i <= 1…

题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of chocolate has price P_i (1 <= P_i <= 1…

https://www.luogu.org/problem/show?pid=2983 题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of…

题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Store features N (1 <= N <= 100,000) kinds of chocolate in essentially unlimited quantities. Each type i of chocolate has price P_i (1 <= P_i <= 1…

传送门 按价格排序后贪心 ——代码 #include <cstdio> #include <iostream> #include <algorithm> int n; long long m, ans; struct node { long long x, y; }p[]; inline long long read() { , f = ; char ch = getchar(); ; ) + (x << ) + ch - '; return x * f;…

P2985 [USACO10FEB]吃巧克力Chocolate Eating 题目描述 Bessie has received N (1 <= N <= 50,000) chocolates from the bulls, but doesn't want to eat them too quickly, so she wants to plan out her chocolate eating schedule for the next D (1 <= D <= 50,000)…

P2983 [USACO10FEB]购买巧克力 题解 注意题目开 long long 贪心策略:价格从低到高,买够为止 反证:若剩下的有一个K”,比K小,那么交换,稳赚不赔 所以,在买K之前,所有比他便宜的都买完了 代码 #include<iostream> #include<cstdio> #include<algorithm> #include<cmath> #include<string> #include<cstring> #…

题目描述 Bessie拿到了N (1 <= N <= 50,000)块巧克力.她决定想个办法吃掉这些巧克力,使得它在吃巧克力的这段时间里,最不开心的一天尽可能的开心.并且一共吃D (1 <= D <= 50,000)天. 每块巧克力有一个开心值H_i (1 <= H_i <= 1,000,000),当某天你吃下那块巧克力时,你将获得那块巧克力的开心值.每一天的开心值是所有当天吃掉的巧克力的总开心值之和.每天晚上Bessie睡觉之后,它的开心值会减半.也就是说,比如昨天B…

题目描述 Farmer John is distributing chocolates at the barn for Valentine's day, and B (1 <= B <= 25,000) of his bulls have a special cow in mind to receive a chocolate gift. Each of the bulls and cows is grazing alone in one of the farm's N (2*B <=…

题目:洛谷P2985. 题目大意:有n块巧克力要吃d天,并且只能按顺序吃.一块巧克力有一个开心值,吃了就能增加开心值.一个人初始开心值为0,且每天早上开心值变为原来的一半.问如何吃巧克力才能使开心值最小的一天开心值最大(每天都按吃完巧克力后计算),且需要输出方案. 解题思路:最大化最小值问题,用二分答案. 贪心地扫描,对于一个答案,如果开心值不到这个答案,就一直吃巧克力即可. 最后输出吃的方案时也用此种贪心法. 注意如果最后巧克力没有吃完,则在最后一天全部吃掉. C++ Code: #inclu…

https://www.luogu.org/problem/show?pid=2984 题目描述 Farmer John is distributing chocolates at the barn for Valentine's day, and B (1 <= B <= 25,000) of his bulls have a special cow in mind to receive a chocolate gift. Each of the bulls and cows is graz…

题目链接 Solution 先直接二分答案,然后贪心判断,一旦少于答案就吃一块. 思路很简单,有一点细节. 一天内可以不吃巧克力. 注意处理最后时没吃完的全部在最后一天吃完. Code #include<bits/stdc++.h> #define ll long long #define N 50008 #define inf 0x3f3f3f3f3f3f3f using namespace std; void in(ll &x) { char ch=getchar();ll f=1…

题目链接:https://www.luogu.org/problemnew/show/P2984 练习SPFA,把FJ当做起点,求出到所有牛的最短路,再把两个牛的相加. #include <cstdio> #include <queue> #include <iostream> #include <algorithm> #include <cstring> using namespace std; ; const int inf = 0x7fff…

题意简叙: FarmerFarmerFarmer JohnJohnJohn有B头奶牛(1<=B<=25000)(1<=B<=25000)(1<=B<=25000),有N(2∗B<=N<=50000)N(2*B<=N<=50000)N(2∗B<=N<=50000)个农场,编号1−N1-N1−N,有M(N−1<=M<=100000)M(N-1<=M<=100000)M(N−1<=M<=100000)条双…

洛谷 P2616 [USACO10JAN]购买饲料II Buying Feed, II https://www.luogu.org/problemnew/show/P2616 题目描述 Farmer John needs to travel to town to pick up K (1 <= K <= 100) pounds of feed. Driving D miles with K pounds of feed in his truck costs D*K cents. The cou…

是非颠倒(逻辑非操作符) "!"是逻辑非操作符,也就是"不是"的意思,非真即假,非假即真.好比小华今天买了一个杯子,小明说:"杯子是白色的",小亮说:"杯子是红色的",小华说:"小明说的不是真话,小亮说的不是假话".猜猜小华买的什么颜色的杯子,答案:红色杯子. 逻辑非操作符值表: 看看下面代码,变量c的值是什么: var a=3; var b=5; var c; c=!(b>a); // b>a…

P2616 [USACO10JAN]购买饲料II Buying Feed, II 题目描述 Farmer John needs to travel to town to pick up K (1 <= K <= 100) pounds of feed. Driving D miles with K pounds of feed in his truck costs D*K cents. The county feed lot has N (1 <= N <= 100) stores…

一.问题描述 0-1背包问题,部分背包问题.分别实现0-1背包的DP算法,部分背包的贪心算法和DP算法. 二.算法原理 (1)0-1背包的DP算法 0-1背包问题:有n件物品和一个容量为W的背包.第i件物品的重量是w[i],价值是v[i].求解将哪些物品装入背包可使这些物品的费用总和不超过背包容量,且价值总和最大.其中每种物品只有一件,可以选择放或者不放. 最优子结构性质:对于0-1问题,考虑重量至多W的最值钱的一包东西.如果去掉其中一个物品j,余下的必是除j以外的n-1件物品中,可以带走的重量…

什么叫做“假学习”? 一.看书 买一堆书,有空看看.看书,这是典型的假学习.看书看不懂还在看,就是假学习,欺骗自己,安慰自己正在学习而已.专业书都写得很好,但大都是写给已经懂的人看的.看书的最大作用就是证明自己看书是学不到东西的,然后只有寻找其他途径. 建议:把书合上,想一想,你想学的东西东西到底是要干什么用的,要掌握到什么程度才够用.实在不行,快速看完,也好过慢慢磨着看完,当你觉得什么时候去看,可以看懂了再去看,还是那句话,不是不看,看的时机对不对而已. 二.听课 听课,记笔记.很常见的假学习…

Description     贝西和其他奶牛们都喜欢巧克力,所以约翰准备买一些送给她们.奶牛巧克力专卖店里 有N种巧克力,每种巧克力的数量都是无限多的.每头奶牛只喜欢一种巧克力,调查显示, 有Ci头奶牛喜欢第i种巧克力,这种巧克力的售价是P.     约翰手上有B元预算,怎样用这些钱让尽量多的奶牛高兴呢?下面举个例子:假设约翰 有50元钱,商店里有S种巧克力:   巧克力品种     单价 高兴的奶牛数量     1     2     3     4     5     5     1   …

Hay For Sale 购买干草 bzoj-1606 Usaco-2008 Dec 题目大意:约翰遭受了重大的损失:蟑螂吃掉了他所有的干草,留下一群饥饿的牛．他乘着容量为C(1≤C≤50000)个单位的马车,去顿因家买一些干草．  顿因有H(1≤H≤5000)包干草,每一包都有它的体积Vi(l≤Vi≤C).约翰只能整包购买,他最多可以运回多少体积的干草呢? 想法:傻逼背包裸题,直接01背包即可. 最后,附上丑陋的代码... ... #include <iostream> #include &…

http://www.lydsy.com/JudgeOnline/problem.php?id=2014 这应该是显然的贪心吧,先排序,然后按花费取 #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm> #include <queue> using na…

题目描述     贝西和其他奶牛们都喜欢巧克力,所以约翰准备买一些送给她们.奶牛巧克力专卖店里 有N种巧克力,每种巧克力的数量都是无限多的.每头奶牛只喜欢一种巧克力,调查显示, 有Ci头奶牛喜欢第i种巧克力,这种巧克力的售价是P.     约翰手上有B元预算,怎样用这些钱让尽量多的奶牛高兴呢?下面举个例子:假设约翰 有50元钱,商店里有S种巧克力:   巧克力品种     单价 高兴的奶牛数量     1    2    3    4    5     5    1    10    7    …

题意: 有n条直线,问他们两两在横坐标开区间(L,R)之间相交的个数 n=50000,暴力肯定就不用想了,如果在纸上画一画可以发现如果两条直线在(L,R)内相交,那么他们与x= L和x=R的交点序数是相反的 所以我们只需要算与x=L的交点,然后根据这些点排序编个号,在与R相交,根据新的交点排个逆序,根据编号求逆序数即可. 需要注意的一点:两种特殊情况如果不与L,R相交,那么如果再这个区间内,必定所有直线都会与之相交,记录下数量. 另一种情况就是,如果两个直线的交点正巧在x=L和x=R时, 这种情…

题意: 给你一个小根堆,从根开始拿,拿走子节点被拿完后才可以拿走父节点,两个人依次拿,谁拿的节点总和大谁获胜,问你谁有必胜策略. 题解: 小根堆中,每个点的权值总是不小于父亲节点的权值.所以无论怎么取,先拿走的数一定 不小于后面拿走的数. 此时双方的最优策略就是:贪心选择能取的数字之中最大的数. #include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<…