F. Video Cards
time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course, Vlad immediately bought only to find out his computer is too old for the new game and needs to be updated.

There are n video cards in the shop, the power of the i-th video card is equal to integer value ai. As Vlad wants to be sure the new game will work he wants to buy not one, but several video cards and unite their powers using the cutting-edge technology. To use this technology one of the cards is chosen as the leading one and other video cards are attached to it as secondary. For this new technology to work it's required that the power of each of the secondary video cards is divisible by the power of the leading video card. In order to achieve that the power of any secondary video card can be reduced to any integer value less or equal than the current power. However, the power of the leading video card should remain unchanged, i.e. it can't be reduced.

Vlad has an infinite amount of money so he can buy any set of video cards. Help him determine which video cards he should buy such that after picking the leading video card and may be reducing some powers of others to make them work together he will get the maximum total value of video power.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 200 000) — the number of video cards in the shop.

The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 200 000) — powers of video cards.

Output

The only line of the output should contain one integer value — the maximum possible total power of video cards working together.

Examples
input
4
3 2 15 9
output
27
input
4
8 2 2 7
output
18
Note

In the first sample, it would be optimal to buy video cards with powers 3, 15 and 9. The video card with power 3should be chosen as the leading one and all other video cards will be compatible with it. Thus, the total power would be 3 + 15 + 9 = 27. If he buys all the video cards and pick the one with the power 2 as the leading, the powers of all other video cards should be reduced by 1, thus the total power would be 2 + 2 + 14 + 8 = 26, that is less than 27. Please note, that it's not allowed to reduce the power of the leading video card, i.e. one can't get the total power3 + 1 + 15 + 9 = 28.

In the second sample, the optimal answer is to buy all video cards and pick the one with the power 2 as the leading. The video card with the power 7 needs it power to be reduced down to 6. The total power would be8 + 2 + 2 + 6 = 18.

题意:一串数字,选择一个作为leading,再找多个Secondary,要求Secondary要能被leading整除,Secondary可以任意减小,leading不能减小,将leading和Secondary加和。问最大的和为多少。

思路:一眼看去没有思路,看了别人的题解。枚举leading,找p*leading—(p+1)*leading之间数字的个数;所以使用前缀和,cnt[num-1]-cnt[num-x-1]为[num-x,num)之间数字的个数。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define LL long long
#define N 200005 int num[N];
int cnt[N];
bool vis[N];
int main()
{
int n;
while(scanf("%d",&n)!=EOF)
{
memset(vis,,sizeof(vis));
memset(cnt,,sizeof(cnt));
int maxn=;
for(int i=; i<n; i++)
{
scanf("%d",&num[i]);
maxn=max(maxn,num[i]);
cnt[num[i]]++;
}
sort(num,num+n);
for(int i=; i<=maxn; i++)
cnt[i]+=cnt[i-];
LL res=;
for(int i=; i<n; i++)
{
LL tmp=;
if(!vis[num[i]])
{
vis[num[i]]=;
for(int j=num[i]; j<=maxn; j+=num[i])
{
tmp+=(cnt[j-]-cnt[j-num[i]-])*(LL)(j-num[i]);
if(j+num[i]>maxn)
tmp+=(cnt[maxn]-cnt[j-])*(LL)j;
}
res=max(tmp,res);
}
}
if(n==)
printf("%d\n",num[]);
else
printf("%I64d\n",res);
}
return ;
}

Codeforces_731F_(前缀和)的更多相关文章

  1. HDU1671——前缀树的一点感触

    题目http://acm.hdu.edu.cn/showproblem.php?pid=1671 题目本身不难,一棵前缀树OK,但是前两次提交都没有成功. 第一次Memory Limit Exceed ...

  2. 【手记】注意BinaryWriter写string的小坑——会在string前加上长度前缀length-prefixed

    之前以为BinaryWriter写string会严格按构造时指定的编码(不指定则是无BOM的UTF8)写入string的二进制,如下面的代码: //将字符串"a"写入流,再拿到流的 ...

  3. ASP.NET Core MVC 配置全局路由前缀

    前言 大家好,今天给大家介绍一个 ASP.NET Core MVC 的一个新特性,给全局路由添加统一前缀.严格说其实不算是新特性,不过是Core MVC特有的. 应用背景 不知道大家在做 Web Ap ...

  4. 如何处理CSS3属性前缀

    今天闲来无聊,重新来说说CSS3前缀的问题.在春节前和@一丝姐姐说起Sass中有关于gradient的mixins.姐姐说: 为什么还要用mixin呢?为什么不使用Autoprefixer?使用Aut ...

  5. context:component-scan" 的前缀 "context" 未绑定。

    SpElUtilTest.testSpELLiteralExpressiontestSpELLiteralExpression(cn.zr.spring.spel.SpElUtilTest)org.s ...

  6. 解决adobe air sdk打包 apk后自动在包名前面加上air. (有个点)前缀的问题

    早就找到了这个方法,但是一直忙没心思写博客. 默认情况下,所有 AIR Android 应用程序的包名称都带 air 前缀.若不想使用此默认行为,可将计算机环境变量 AIR_NOANDROIDFLAI ...

  7. adobe air类app 接入腾讯开放平台移动游戏使用带tencent包名前缀的问题

    作者:Panda Fang 出处:http://www.cnblogs.com/lonkiss/p/4209159.html 原创文章,转载请注明作者和出处,未经允许不可用于商业营利活动 ------ ...

  8. [LeetCode] Implement Trie (Prefix Tree) 实现字典树(前缀树)

    Implement a trie with insert, search, and startsWith methods. Note:You may assume that all inputs ar ...

  9. [LeetCode] Longest Common Prefix 最长共同前缀

    Write a function to find the longest common prefix string amongst an array of strings. 这道题让我们求一系列字符串 ...

随机推荐

  1. WPS for Linux字体配置(Ubuntu 16.04)

    错误提示: 解决方法: 从http://bbs.wps.cn/thread-22355435-1-1.html下载字体库,离线版本:(链接: https://pan.baidu.com/s/1i5dz ...

  2. logout退出功能是怎么实现的?login登陆功能室怎么实现的

    logout退出功能是怎么实现的?login登陆功能室怎么实现的 login就是登陆成功的时候,在session里面创建好用户对应的数据. logout就是登出的时候,在session里面销毁用户对应 ...

  3. apache2 ubuntu18.04 配置虚拟端口

    修改3个文件/etc/apache2/apache2.conf/etc/apache2/ports.conf/etc/apache2/sites-available/000-default.conf ...

  4. Ajax跨域、Json跨域、Socket跨域和Canvas跨域等同源策略限制的解决方法

    同源是指同样的协议.域名.port,三者都同样才属于同域.不符合上述定义的请求,则称为跨域. 相信每一个开发者都曾遇到过跨域请求的情况,尽管情况不一样,但问题的本质都能够归为浏览器出于安全考虑下的同源 ...

  5. ORA-00904:&quot;T1&quot;.&quot;AREA_ID&quot; :标识符无效

    1.错误描写叙述 ORA-00904:"T1"."AREA_ID" :标识符无效 00904 . 00000 - "%s:invalid identi ...

  6. 逆向工程之App脱壳

    http://www.cnblogs.com/ludashi/p/5725743.html iOS逆向工程之App脱壳 本篇博客以微信为例,给微信脱壳."砸壳"在iOS逆向工程中是 ...

  7. Configuration.SectionGroups

    对于一个空的配置文件,默认自带的sectiongroups 默认有10个section节点 1 ConfigurationSectionGroupName=system.runtime.seriali ...

  8. POJ1061 青蛙的约会 exgcd

    这个题虽然很简单,但是有一个比较坑的地方,就是gcd不一定是1,有可能是别的数.所以不能return 1,而是return a; 题干: Description 两只青蛙在网上相识了,它们聊得很开心, ...

  9. bzoj1345

    贪心 这并没有想清楚就看题解了... 看上去肯定是贪心,那么怎么贪呢?事实上,我们想一下,假设max(a[i],a[i+1])中a[i]没有合并,那么后面取max肯定是a[i+1],因为如果后面合并之 ...

  10. Map类型介绍与遍历

    声明:本文非原创: 在程序员开发过程中,Map有着利用率占比是非常高:很多时间我们只知其用,不知其理:写这个随笔的目的也是希望对伙伴们对Map的理解有一点帮助. 类型介绍 java自带各种Map类.统 ...