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

B. Making a String

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

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

3
2 5 5

output

11

input

3
1 1 2

output

3

Note

哎  睡着了 没做成！

大体题意：

字符串每个字母最大出现次数告诉你，并且不能有两个字母出现次数一样！

思路：

读到数组里，用map记录出现次数，相应的减少就行了！

注意：

1.sum要开long long 否则和会溢出！

2.不能无限的减，只有数大于0，sum才加。

代码如下：

#include<iostream>
#include<cmath>
#include<cstdio>
#include<map>
using namespace std;
int main()
{
    int n,a[30];
    while(~scanf("%d",&n)){
        map<int,int>m;
        for (int i= 0; i < n; ++i){scanf("%d",&a[i]);m[a[i]]++;}
        long long sum = 0;
        for (int i = 0; i < n; ++i){
                int k = a[i];
                if (m[k] > 1){
                    m[k]--;k--;
                    while(m[k])k--;
                }
                m[k]++;
                if (k>0)sum+=k;
        }
        printf("%I64d\n",sum);
    }
    return 0;
}