A. Boredom
来源:互联网 发布:金融科技 知乎 编辑:程序博客网 时间:2024/05/07 05:57
Alex doesn't like boredom. That's why whenever he gets bored, he comes up with games. One long winter evening he came up with a game and decided to play it.
Given a sequence a consisting of n integers. The player can make several steps. In a single step he can choose an element of the sequence (let's denote it ak) and delete it, at that all elements equal to ak + 1 and ak - 1 also must be deleted from the sequence. That step brings ak points to the player.
Alex is a perfectionist, so he decided to get as many points as possible. Help him.
The first line contains integer n (1 ≤ n ≤ 105) that shows how many numbers are in Alex's sequence.
The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 105).
Print a single integer — the maximum number of points that Alex can earn.
21 2
2
31 2 3
4
91 2 1 3 2 2 2 2 3
10
Consider the third test example. At first step we need to choose any element equal to 2. After that step our sequence looks like this [2, 2, 2, 2]. Then we do 4 steps, on each step we choose any element equals to 2. In total we earn 10 points.
解题说明:此题是一道动态规划题,做法是先存下每个数的个数放在c中,消除一个数i,会获得c[i]*i的值(因为可以消除c[i]次),如果从0的位置开始向右消去,那么,消除数i时,i-1可能选择了消除,也可能没有,
如果消除了i-1,那么i值就已经不存在,dp[i] = dp[i-1],如果没有被消除,那么dp[i] = dp[i-2]+ c[i]*i。在上面两者中取最大值即可。
#include<iostream>#include<cstdio>#include<cmath>#include<algorithm>#include<cstdlib>#include<cstring>using namespace std;long long a[100010],ans[100010];int main(){int n,i,k;cin>>n;for(i=0;i<n;i++){scanf("%d",&k);a[k]++;}ans[1]=a[1];for(i=2;i<=100002;i++){ans[i]=max(ans[i-1],ans[i-2]+i*a[i]);}cout<<ans[100002]<<endl;return 0;}
- A. Boredom
- A. Boredom
- codeforces 455A Boredom
- CodeForces 455A Boredom
- 455A Boredom
- 455A - Boredom
- CodeForces 455A - Boredom
- CodeForces 455A Boredom
- Codeforces-455A-Boredom
- codeforces 455A Boredom dp
- Codeforces 455A Boredom(高效)
- CF 455A(Boredom-dp)
- 【dp】 codeforces 455A Boredom
- Codeforces 455A Boredom (dp)
- CF 445A Boredom DP
- #260 (div.1) A.Boredom
- CodeForces 455A Boredom (dp)
- cf 155A Boredom dp
- 【程序员应该知道的】硬盘基本知识
- Binary Tree Postorder Traversal
- Zookeeper集群搭建
- 2014华为机试题---字符压缩
- 网站RSS的使用
- A. Boredom
- 基于Grunt构建一个JavaScript库
- 最大流问题
- GDB 内存断点
- “E576: viminfo: 缺少 '>' 位于行: ” 或者是“ E576: viminfo: Missing '>' in line: ”
- 链式前向星以及代码实现
- Spring-SpringMVC-Hibernate整合
- 安慰
- matlab保存figure中的图片去掉白边