Investable Periods 🐿️
MathWorks● MediumFULLTIMEOAProblem statement
A trading firm predicts the stock prices of a commodity for the next n days. A period of consecutive days is considered investable if the maximum price in the period is max_price, and the minimum price in the period is min_price. Find the number of investable periods in the next n days.
More formally, given an array price of length n, find the number of subarrays in which the maximum element is max_price and the minimum element is min_price.
Note: A subarray is a sequence of consecutive elements of the array.
Function
countInvestablePeriods(price: int[], max_price: int, min_price: int) → long
Complete the function countInvestablePeriods in the editor below.
countInvestablePeriods has the following parameters:
int price[n]: the predicted prices for the nextndaysint max_price: the maximum price of an investable periodint min_price: the minimum price of an investable period
Returns
long integer: the number of investable periods
Examples
Example 1
price = [4, 5, 3, 3, 1]max_price = 5min_price = 3return = 4Here, the periods [4, 5, 3], [4, 5, 3, 3], [5, 3], and [5, 3, 3] are investable.
Example 2
price = [2, 2, 1, 5, 1]max_price = 2min_price = 1return = 2The periods [2, 2, 1] and [2, 1] are investable.
Example 3
price = [1, 2, 3, 2]max_price = 3min_price = 2return = 3Hola!! This testcase was added on the 18th of May, 2025~ You can find the source image in the problem source section below. The consecutive periods [2, 3], [2, 3, 2], and [3, 2] are investable as the min and max of these subarrays equal min_price and max_price respective. There are no otehr periods that satisfy this constraint. So, answer is 3.
Constraints
1 ≤ n ≤ 10^51 ≤ price[i] ≤ 10^91 ≤ min_price ≤ max_price ≤ 10^9