Leetcode 1395. Count Number of Teams

class Solution:
    def numTeams(self, rating: List[int]) -> int:
        count = 0
        n = len(rating)
        for i in range(n):
            for j in range(i+1, n):
                for k in range(j+1, n):
                    if rating[i] < rating[j] and rating[j] < rating[k]:
                        count += 1
                    elif rating[i] > rating[j] and rating[j] > rating[k]:
                        count += 1
        return count

class Solution:
    def numTeams(self, rating: List[int]) -> int:
        count = 0
        n = len(rating)
        for i in range(n):
            greater_left = 0
            greater_right = 0
            less_left = 0
            less_right = 0
            for j in range(i):
                if rating[i] > rating[j]:
                    less_left += 1
                else:
                    greater_left += 1
            for j in range(i+1, n):
                if rating[i] > rating[j]:
                    less_right += 1
                else:
                    greater_right += 1
            count += greater_left * less_right + greater_right * less_left
        return count

class Solution:
    def numTeams(self, rating: List[int]) -> int:
        count = 0
        n = len(rating)
        greater_left = collections.defaultdict(int)
        greater_right = collections.defaultdict(int)
        less_left = collections.defaultdict(int)
        less_right = collections.defaultdict(int)
        for i in range(n):
            for j in range(i+1, n):
                if rating[i] > rating[j]:
                    less_right[i] += 1
                    greater_left[j] += 1
                else:
                    greater_right[i] += 1
                    less_left[j] += 1
        for i in range(n):
            count += greater_left[i] * less_right[i] + greater_right[i] * less_left[i]
        return count