[Leet Code] Count Number of Teams

Leetcode: https://leetcode.com/problems/count-number-of-teams/

Problem:

There are n soldiers standing in a line. Each soldier is assigned a unique rating value.

You have to form a team of 3 soldiers amongst them under the following rules:

• Choose 3 soldiers with index (i, j, k) with rating (rating[i], rating[j], rating[k]).
• A team is valid if: (rating[i] < rating[j] < rating[k]) or (rating[i] > rating[j] > rating[k]) where (0 <= i < j < k < n).

Return the number of teams you can form given the conditions. (soldiers can be part of multiple teams).

Example 1:

Input: rating = [2,5,3,4,1]
Output: 3
Explanation: We can form three teams given the conditions. (2,3,4), (5,4,1), (5,3,1).

Example 2:

Input: rating = [2,1,3]
Output: 0
Explanation: We can't form any team given the conditions.

Example 3:

Input: rating = [1,2,3,4]
Output: 4

Constraints:

• n == rating.length
• 1 <= n <= 200
• 1 <= rating[i] <= 10^5

Solution:

class Solution(object):
    def numTeams(self, rating):
        """
        :type rating: List[int]
        :rtype: int
        """
        counter = 0
        for i in range(len(rating)):
            for j in range(len(rating)):
                for k in range(len(rating)):
                    if i < j < k and ((rating[i] < rating[j] < rating[k]) or (rating[i] > rating[j] > rating[k])):
                        counter += 1
                        
        return counter