zoukankan      html  css  js  c++  java
  • codeforces-455A

    A. Boredom
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    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.

    Input

    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).

    Output

    Print a single integer — the maximum number of points that Alex can earn.

    Examples
    input
    2
    1 2
    output
    2
    input
    3
    1 2 3
    output
    4
    input
    9
    1 2 1 3 2 2 2 2 3
    output
    10
    Note

    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.

     这道题的大概意思是输入n个数字,每次从中取出一个数k,并且将k-1和k+1抹去,然后继续取,直到取完为止,求最后取出数最大的和是多少。

    想法是使用map函数,记录每个数的次数,然后从0到最大值遍历,使用动态规划的思想,每次记录两个数,一个是k-2的最大值,一个是k-1的最大值,然后用max(k-1,k-2+map[k]*k)求得当前最大值

    #include<iostream>
    #include<map>
    #include<algorithm>
    using namespace std;
    
    map<long, int>mp;
    
    int main()
    {
        int n, num, p, q, maxn = 0;
        cin >> n;
        for (int i = 0;i < n;i++)
        {
            getchar();
            cin >> num;
            mp[num]++;
            if (num > maxn)
                maxn = num;
        }
        if (n == 1)
            cout << num << endl;
        else
        {
            p = q = 0;
            for (long long i = 1;i <= maxn;i++)
            {
                long long temp = i*mp[i] + q;
                q = max(q, p);
                p = temp;
            }
            cout << max(p,q) << endl;
        }
        return 0;
    }
    #include <cstdio>
    #include <cstring>
    #include <iostream>
    #include <algorithm>
    
    using namespace std;
    typedef long long ll;
    const int maxn = 1e5+5;
    
    int n, arr, c[maxn];
    
    int main () {
        cin >> n;
        memset(c, 0, sizeof(c));
    
        for (int i = 0; i < n; i++) {
            cin >> arr;
            c[arr]++;
        }
    
        ll p = 0, q = 0;
    
        for (int i = 1; i < maxn; i++) {
    
            ll tmp = q + 1LL * i * c[i];
            q = max(p, q);
            p = tmp;
        }
    
        cout << max(p, q) << endl;
        return 0;
    }
  • 相关阅读:
    Android代码执行adb shell top命令读取结果
    Android8.0+跨应用发送广播和跨应用启动前台服务
    Android代码执行adb shell命令
    关于参数获取的那些事儿
    c# 如何处理自定义消息
    esp32 mqtt协议上报 dht11温湿度数据到onenet 指令下发控制开关灯
    swoole-simps自搭mqtt服务器,完美实现订阅,发布并存到mysql
    stm32f103c8t6+esp8266+dht11 mqtt上传温湿度到阿里云
    使用ST-Link下载程序出现Error:Flash Download Failed-“Cortex-M3“ 解决详细步骤(附图)
    stm32f407 oled iic例程,成功点亮oled屏
  • 原文地址:https://www.cnblogs.com/chenruijiang/p/8182908.html
Copyright © 2011-2022 走看看