AIM Tech Round (Div. 2)-B. Making a String（贪心）

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You are given an alphabet consisting of n letters, your task is to make a string of the maximum possible length so that the following conditions are satisfied:

the i-th letter occurs in the string no more than ai times;
the number of occurrences of each letter in the string must be distinct for all the letters that occurred in the string at least once.

Input

The first line of the input contains a single integer n (2 ≤ n ≤ 26) — the number of letters in the alphabet.

The next line contains n integers ai (1 ≤ ai ≤ 109) — i-th of these integers gives the limitation on the number of occurrences of the i-th character in the string.

Output

Print a single integer — the maximum length of the string that meets all the requirements.

Sample test(s)
input
32 5 5
output
11
input
31 1 2
output
3

Note

For convenience let's consider an alphabet consisting of three letters: "a", "b", "c". In the first sample, some of the optimal strings are: "cccaabbccbb", "aabcbcbcbcb". In the second sample some of the optimal strings are: "acc", "cbc".

题意：

给你n个数，要你求出不能相同，而且最大的数出来，所以只要每个数取一次出来，然后多出来的减一，退去后面。只要保证每个数都是一个就ok了。

AC代码：

#include<iostream>#include<functional>#include<algorithm>#include<cstring>#include<string>#include<vector>#include<cstdio>#include<cmath>#include<map>using namespace std;#define CRL(a) memset(a,0,sizeof(a))typedef unsigned __int64 LL;typedef  __int64 ll;#define CMP bool cmp(const node& a,const node& b){return a.R<b.R||(a.R==b.R&&a.L<b.L); }const int T = 503000;const int mod = 1000000007;int a[55];int main(){#ifdef zsc    freopen("input.txt","r",stdin);#endifint n,m,i,j,k;while(~scanf("%d",&n)){map< int,int,greater<int> > ve;for(i=0;i<n;++i){scanf("%d",&a[i]);ve[a[i]]++;}map< int,int,greater<int> >::iterator it;ll sum = 0;for(it=ve.begin();it!=ve.end();++it){sum += it->first;while(it->second>1){if(it->first-1!=0)ve[it->first-1]++;it->second--;}}printf("%I64d\n",sum);}    return 0;}

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