Leetcode 1395. 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: 3Explanation: 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: 0Explanation: We can't form any team given the conditions.
Example 3:
Input: rating = [1,2,3,4]Output: 4
?
Constraints:
n == rating.length3 <= n <= 10001 <= rating[i] <= 105All the integers in?
rating?are?unique.
遍歷所有位置，計算出來4個參數(shù)的值，然后4個參數(shù)的乘積和就是了。
居然沒想到，，，，汗顏。
Runtime43 ms
Beats
38.35%
Memory42.6 MB
Beats
54.39%
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