codeforces #345 div 2 B. Beautiful Paintings (暴力)
题目链接 题意:给出一个数列,按照最好的策略排序使得a[i+1]>a[i]的对数尽可能多,问最多的对数是多少。 思路:类似计数排序?
/* ***********************************************
Author :111qqz
Created Time :2016年03月07日 星期一 17时06分48秒
File Name :code/cf/#345/B.cpp
************************************************ */
1#include <cstdio>
2#include <cstring>
3#include <iostream>
4#include <algorithm>
5#include <vector>
6#include <queue>
7#include <set>
8#include <map>
9#include <string>
10#include <cmath>
11#include <cstdlib>
12#include <ctime>
13#define fst first
14#define sec second
15#define lson l,m,rt<<1
16#define rson m+1,r,rt<<1|1
17#define ms(a,x) memset(a,x,sizeof(a))
18typedef long long LL;
19#define pi pair < int ,int >
20#define MP make_pair
1using namespace std;
2const double eps = 1E-8;
3const int dx4[4]={1,0,0,-1};
4const int dy4[4]={0,-1,1,0};
5const int inf = 0x3f3f3f3f;
6const int N=1E3+7;
7int n ;
8int a[N];
9int cnt[N];
10int num[N];
11int sum[N];
12int main()
13{
14 #ifndef ONLINE_JUDGE
15 freopen("code/in.txt","r",stdin);
16 #endif
1 cin>>n;
2 ms(cnt,0);
3 ms(num,0);
4 ms(sum,0);
5 for ( int i = 1 ; i <= n ; i++)
6 {
7 cin>>a[i];
8 cnt[a[i]]++;
9 }
10 if (n==1)
11 {
12 puts("0");
13 return 0 ;
14 }
15 if (n==2)
16 {
17 if (a[1]==a[2])
18 {
19 puts("0");
20 }
21 else
22 {
23 puts("1");
24 }
25 return 0;
26 }
1 int mx = -1;
2 for ( int i = 1 ; i <= 1000 ; i++)
3 {
4 num[cnt[i]]++;
5 mx = max(mx,cnt[i]);
6 }
1 for ( int i = mx ; i >= 1 ; i --)
2 {
3 sum[i] = sum[i+1]+num[i];
4 }
1 int ans = 0 ;
2 for ( int i = 1 ; i <= mx ; i++)
3 {
4 ans +=sum[i]-1;
5// cout<<"sum[i]:"<<sum[i]<<endl;
6 }
7 cout<<ans<<endl;
1 #ifndef ONLINE_JUDGE
2 fclose(stdin);
3 #endif
4 return 0;
5}