Count Number of Teams
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
3We can form three teams given the conditions: (2,3,4), (5,4,1), and (5,3,1).
Example 2
Input
rating = [2,1,3]Output
0We can't form any team given the conditions.
Constraints
- n == rating.length
- 3 <= n <= 1000
- 1 <= rating[i] <= 10^5
- All the integers in
ratingare unique.