Problem Brief

Investable Periods 🐿️

FULLTIMEOA

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 Description

Complete the function countInvestablePeriods in the editor below.

countInvestablePeriods has the following parameters:

int price[n]: the predicted prices for the next n days
int max_price: the maximum price of an investable period
int min_price: the minimum price of an investable period

Returns

long integer: the number of investable periods

1Example 1

Input

price = [4, 5, 3, 3, 1], max_price = 5, min_price = 3

Output

Explanation

Here, the periods [4, 5, 3], [4, 5, 3, 3], [5, 3], and [5, 3, 3] are investable.

2Example 2

Input

price = [2, 2, 1, 5, 1], max_price = 2, min_price = 1

Output

Explanation

The periods [2, 2, 1] and [2, 1] are investable.

3Example 3

Input

price = [1, 2, 3, 2], max_price = 3, min_price = 2

Output

Explanation

Hola!! 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

Limits and guarantees your solution can rely on.

1 ≤ n ≤ 10^5

1 ≤ price[i] ≤ 10^9

1 ≤ min_price ≤ max_price ≤ 10^9