Problem:
Score : 200 points

Problem Statement

We have sticks numbered 1, \cdots, N. The length of Stick i (1 \leq i \leq N) is L_i.

In how many ways can we choose three of the sticks with different lengths that can form a triangle?

That is, find the number of triples of integers (i, j, k) (1 \leq i < j < k \leq N) that satisfy both of the following conditions:

L_i, L_j, and L_k are all different.

There exists a triangle whose sides have lengths L_i, L_j, and L_k.

Constraints

1 \leq N \leq 100

1 \leq L_i \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
L_1 L_2 \cdots L_N

Output

Print the number of ways to choose three of the sticks with different lengths that can form a triangle.

Sample Input 1

5
4 4 9 7 5

Sample Output 1

5

The following five triples (i, j, k) satisfy the conditions: (1, 3, 4), (1, 4, 5), (2, 3, 4), (2, 4, 5), and (3, 4, 5).

Sample Input 2

6
4 5 4 3 3 5

Sample Output 2

8

We have two sticks for each of the lengths 3, 4, and 5. To satisfy the first condition, we have to choose one from each length.

There is a triangle whose sides have lengths 3, 4, and 5, so we have 2 ^ 3 = 8 triples (i, j, k) that satisfy the conditions.

Sample Input 3

10
9 4 6 1 9 6 10 6 6 8

Sample Output 3

39

Sample Input 4

2
1 1

Sample Output 4

0

No triple (i, j, k) satisfies 1 \leq i < j < k \leq N, so we should print 0.

Solution in C (GCC 9.2.1) (judge verdict: Accepted)

#include <stdio.h>

int main()
{
  int n;
  scanf("%d",&n);
  int l[n];
  int i;
  i = 0;
  while (i < n)
  {
    scanf("%d",&l[i]);
    i++;
  }
  if (n < 3)
  {
    printf("0");
    return (0);
  }
  int j = 0;
  i = 0;
  int k = 0;
  int cnt = 0;
  while (i < n)
  {
    j = i + 1;
    while (j < n)
    {
      k = j + 1;
      while (k < n)
      {
      	if ((l[i] + l[k] > l[j] && l[i] + l[j] > l[k] && l[k] + l[j] > l[i]) && l[i] != l[k] && l[i] != l[j] && l[k] != l[j])
      	{
          //printf("%d:%d:%d\n",l[i],l[j],l[k]);
          cnt++;
        }
        k++;
      }
      j++;
    }
    i++;
  }
  printf("%d",cnt);
}