Codeforces Round #304 (Div. 2) B

B. Soldier and Badges
time limit per test 3 seconds memory limit per test 256 megabytes

input standard input output standard output

Colonel has n badges. He wants to give one badge to every of hisn soldiers. Each badge has a coolness factor, which shows how much it's owner
reached. Coolness factor can be increased by one for the cost of one coin.

For every pair of soldiers one of them should get a badge with strictly higher factor than the second one. Exact values of their factors aren't important, they just need to have distinct factors.

Colonel knows, which soldier is supposed to get which badge initially, but there is a problem. Some of badges may have the same factor of coolness. Help him and calculate how much money has to be paid for making all badges have different factors of coolness.

Input
First line of input consists of one integer n (1 ≤ n ≤ 3000).

Next line consists of n integers ai (1 ≤ ai ≤ n),
which stand for coolness factor of each badge.

Output
Output single integer — minimum amount of coins the colonel has to pay.

Sample test(s)

Input

4
1 3 1 4

Output

1

Input

5
1 2 3 2 5

Output

2

Note
In first sample test we can increase factor of first badge by 1.

In second sample test we can increase factors of the second and the third badge by1.

题意：其实就是问你最少加几个1，使得这串数字各不相同。

思路：sort一下就好，然后把相同的+1，直到变成不同的数为止，水题。

代码如下：

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int N = 3005;
int a
, b
;
int main()
{
int n = 0;
while(~scanf("%d", &n))
{
for(int i = 1; i <= n; i++)
{
scanf("%d", &a[i]);
}
sort(a+1, a+n+1);
int ans = 0;
for(int i = 1; i <= n; i++)
{
for(int j = i+1; j <= n; j++)
{
if(a[i] == a[j])
{
ans++;
a[j]++;
}
}
}
printf("%d\n", ans);
}
return 0;
}