zoukankan      html  css  js  c++  java
  • Codeforces Round #345 (Div. 2)——B. Beautiful Paintings(贪心求上升序列个数)

    B. Beautiful Paintings
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    There are n pictures delivered for the new exhibition. The i-th painting has beauty ai. We know that a visitor becomes happy every time he passes from a painting to a more beautiful one.

    We are allowed to arranged pictures in any order. What is the maximum possible number of times the visitor may become happy while passing all pictures from first to last? In other words, we are allowed to rearrange elements of a in any order. What is the maximum possible number of indices i (1 ≤ i ≤ n - 1), such that ai + 1 > ai.

    Input

    The first line of the input contains integer n (1 ≤ n ≤ 1000) — the number of painting.

    The second line contains the sequence a1, a2, ..., an (1 ≤ ai ≤ 1000), where ai means the beauty of the i-th painting.

    Output

    Print one integer — the maximum possible number of neighbouring pairs, such that ai + 1 > ai, after the optimal rearrangement.

    Examples
    input
    5
    20 30 10 50 40
    
    output
    4
    
    input
    4
    200 100 100 200
    
    output
    2
    
    Note

    In the first sample, the optimal order is: 10, 20, 30, 40, 50.

    In the second sample, the optimal order is: 100, 200, 100, 200.

    题意:求最多的上升序列的个数,用map比数组快多,做法:切蛋糕一样每次切一层 

    代码:

    #include<iostream>
    #include<algorithm>
    #include<vector>
    #include<sstream>
    #include<map>
    using namespace std;
    int main(void)
    {
    	int t,n,i,j,be,sum,ans;
    	while (cin>>n)
    	{
    		map<int,int>list;
    		for (i=0; i<n; i++)
    		{
    			cin>>be;
    			list[be]++;
    		}
    		ans=0;
    		while (n)//每次
    		{
    			int num=0;
    			for (map<int,int>::iterator it=list.begin(); it!=list.end(); it++)
    			{
    				if(it->second>0)
    				{
    					(it->second)--;
    					n--;
    					num++;
    				}
    			}
    			ans=ans+num-1;//两个以上才算一个上升序列
    		}
    		cout<<ans<<endl;
    	}
    	return 0;
    }
  • 相关阅读:
    HDU3555:Bomb
    入门OJ:售货员的难题
    Zju1100 Mondriaan
    与图论的邂逅08:树上倍增
    入门OJ:八中生成树2
    Poj2286 The Rotation Game
    P1379 八数码难题
    [SCOI2005]骑士精神
    与图论的邂逅07:K短路
    [Usaco2007 Feb]Cow Party
  • 原文地址:https://www.cnblogs.com/Blackops/p/5356409.html
Copyright © 2011-2022 走看看