CF F. Shovels Shop(前缀和预处理+贪心+dp)
2 seconds
256 megabytes
standard input
standard output
There are nn shovels in the nearby shop. The ii -th shovel costs aiai bourles.
Misha has to buy exactly kk shovels. Each shovel can be bought no more than once.
Misha can buy shovels by several purchases. During one purchase he can choose any subset of remaining (non-bought) shovels and buy this subset.
There are also mm special offers in the shop. The jj -th of them is given as a pair (xj,yj)(xj,yj) , and it means that if Misha buys exactly xjxj shovels during one purchase then yjyj most cheapest of them are for free (i.e. he will not pay for yjyj most cheapest shovels during the current purchase).
Misha can use any offer any (possibly, zero) number of times, but he cannot use more than one offer during one purchase (but he can buy shovels without using any offers).
Your task is to calculate the minimum cost of buying kk shovels, if Misha buys them optimally.
The first line of the input contains three integers n,mn,m and kk (1≤n,m≤2⋅105,1≤k≤min(n,2000)1≤n,m≤2⋅105,1≤k≤min(n,2000) ) — the number of shovels in the shop, the number of special offers and the number of shovels Misha has to buy, correspondingly.
The second line of the input contains nn integers a1,a2,…,ana1,a2,…,an (1≤ai≤2⋅1051≤ai≤2⋅105 ), where aiai is the cost of the ii -th shovel.
The next mm lines contain special offers. The jj -th of them is given as a pair of integers (xi,yi)(xi,yi) (1≤yi≤xi≤n1≤yi≤xi≤n ) and means that if Misha buys exactly xixi shovels during some purchase, then he can take yiyi most cheapest of them for free.
Print one integer — the minimum cost of buying kk shovels if Misha buys them optimally.
7 4 5
2 5 4 2 6 3 1
2 1
6 5
2 1
3 1
7
9 4 8
6 8 5 1 8 1 1 2 1
9 2
8 4
5 3
9 7
17
5 1 4
2 5 7 4 6
5 4
17
In the first example Misha can buy shovels on positions 11 and 44 (both with costs 22 ) during the first purchase and get one of them for free using the first or the third special offer. And then he can buy shovels on positions 33 and 66 (with costs 44 and 33 ) during the second purchase and get the second one for free using the first or the third special offer. Then he can buy the shovel on a position 77 with cost 11 . So the total cost is 4+2+1=74+2+1=7 .
In the second example Misha can buy shovels on positions 11 , 22 , 33 , 44 and 88 (costs are 66 , 88 , 55 , 11 and 22 ) and get three cheapest (with costs 55 , 11 and 22 ) for free. And then he can buy shovels on positions 66 , 77 and 99 (all with costs 11 ) without using any special offers. So the total cost is 6+8+1+1+1=176+8+1+1+1=17 .
In the third example Misha can buy four cheapest shovels without using any special offers and get the total cost 1717 .
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = *1e5+;
int a[maxn];
/*s表示前i件物品中的总花费,
g代表前i件物品中最多能免费的件数
dp代表前i件物品中最大能够节省的钱
*/
int s[maxn],g[maxn],dp[maxn]; int main(){
int n,m,k;
cin>>n>>m>>k;
for( int i=; i<=n; i++ ){
cin>>a[i];
}
sort(a+,a++n);
for( int i=; i<=n; i++ ){
s[i]=s[i-]+a[i];//前缀和
}
for( int i=; i<=m; i++ ){
int x,y;
cin>>x>>y;
g[x]=max(g[x],y);//最大减少数
}
for( int i=; i<=k; i++ ){
for( int j=; j<i; j++ ){
dp[i]=max(dp[i],dp[j]+s[j+g[i-j]]-s[j]);
}
}
cout<<s[k]-dp[k];
return ;
}
CF F. Shovels Shop(前缀和预处理+贪心+dp)的更多相关文章
- Codeforces Round #552 (Div. 3) F. Shovels Shop (前缀和预处理+贪心+dp)
题目:http://codeforces.com/contest/1154/problem/F 题意:给你n个商品,然后还有m个特价活动,你买满x件就把你当前的x件中最便宜的y件价格免费,问你买k件花 ...
- cf F. Shovels Shop
https://codeforces.com/contest/1154/problem/F 给定m个折扣 每个折扣的{x,y}的意思是每次购买如果买到确切的x只铲子就其中的最便宜的y只铲子免付: 先贪 ...
- F. Shovels Shop 背包DP
题意: 商店里有n把铲子 每个铲子有其标价 一个人要买k吧 有m个优惠政策 每个优惠政策有两个元素x,y 表示 正好买x个铲子的时候 这x个铲子中最便宜的y个铲子免单 求用最少的前买到k个铲子 ...
- Codeforces Round #552 (Div. 3) F. Shovels Shop(dp)
题目链接 大意:给你n个物品和m种优惠方式,让你买k种,问最少多少钱. 思路:考虑dpdpdp,dp[x]dp[x]dp[x]表示买xxx种物品的最少花费,然后遍历mmm种优惠方式就行转移就好了. # ...
- CF 628C --- Bear and String Distance --- 简单贪心
CF 628C 题目大意:给定一个长度为n(n < 10^5)的只含小写字母的字符串,以及一个数d,定义字符的dis--dis(ch1, ch2)为两个字符之差, 两个串的dis为各个位置上字符 ...
- BZOJ-1587|前缀和 预处理 dp||叶子合并leaves
叶子合并leaves Description 在一个美丽的秋天,丽丽每天都经过的花园小巷落满了树叶,她决定把树叶堆成K堆,小巷是笔直的 共有N片树叶(树叶排列也是笔直的),每片树叶都有一个重量值,并且 ...
- HDU 5550 - Game Rooms(DP + 前缀和预处理)
链接: http://acm.hdu.edu.cn/showproblem.php?pid=5550 题意: 一个大楼有n(2≤n≤4000)层,每层可以建一个乒乓球房或者一个游泳房,且每种房间在大楼 ...
- LightOJ-1007-Mathematically Hard-欧拉函数打表+前缀和+预处理
Mathematically some problems look hard. But with the help of the computer, some problems can be easi ...
- 【BZOJ-3174】拯救小矮人 贪心 + DP
3174: [Tjoi2013]拯救小矮人 Time Limit: 1 Sec Memory Limit: 128 MBSubmit: 686 Solved: 357[Submit][Status ...
随机推荐
- 爬虫 http原理,梨视频,github登陆实例,requests请求参数小总结
回顾:http协议基于请求响应的方式,请求:请求首行 请求头{'keys':vales} 请求体 :响应:响应首行,响应头{'keys':'vales'},响应体. import socket soc ...
- python学习第34天
# 互斥锁# 进程之间的数据共享 # 关于数据安全的问题# 进程池(自己了解,后面线程部分还会讲) # from multiprocessing import Pool# 线程的概念 (面试的重点)# ...
- js数据结构与算法——字典与散列表
<script> //创建字典 function Dictionary(){ var items = {}; this.set = function(key,value){ //向字典添加 ...
- stderr和stdout详细解说
今天又查了一下fprintf,其中对第一个参数stderr特别感兴趣. int fprintf(FILE *stream,char *format,[argument]): 在此之前先区分一下:pri ...
- 2019年春季学期第三周作业 ----PTA作业
题目 判断上三角矩阵 上三角矩阵指主对角线以下的元素都为0的矩阵:主对角线为从矩阵的左上角至右下角的连线. 本题要求编写程序,判断一个给定的方阵是否上三角矩阵. 输入格式: 输入第一行给出一个正整数T ...
- P3436 [POI2006]PRO-Professor Szu
P3436 [POI2006]PRO-Professor Szu 题目描述 n个别墅以及一个主建筑楼,从每个别墅都有很多种不同方式走到主建筑楼,其中不同的定义是(每条边可以走多次,如果走边的顺序有一条 ...
- centOS设置开机自启
原文:https://blog.csdn.net/txz317/article/details/49683439 1.利用 chkconfig 来配置启动级别 在CentOS或者RedHat其他系统下 ...
- python之地基(三)
一.引用计数和垃圾回收机制 当一个执行程序完毕后,回收变量所占据的内存. 当引用计数变为0的时候,回收变量所占据的内存. a=100 print(id(a)) a=input('==>:') # ...
- Centos7创建支持ssh服务的docker镜像
如何在centos7中使用docker创建一个支持ssh连接的容器 1.拉取centos7.4镜像(由于7.4目前是最稳定的版本,所以推荐使用centos7.4) docker pull centos ...
- centos防火墙控制与转发端口
一.使用防火墙 systemctl控制防火墙 systemctl status/start/stop/restart firewalld 如开启防火墙: $ systemctl start firew ...