Total Price Fluctuation
A company records the daily price of a product in prices. The fluctuation during a contiguous, non-empty period is the difference between its highest and lowest prices.
Return the sum of the fluctuations for all possible periods.
Method Signature
long totalPriceFluctuation(List<Integer> prices)
Parameters
prices contains the product price recorded on each day.
Return Value
Return the sum of the price fluctuations across all contiguous, non-empty periods.
Constraints
1 <= prices.size() <= 1,000-1,000,000,000 <= prices.get(i) <= 1,000,000,000
Examples
Example 1
totalPriceFluctuation(prices = [4, 1, 3])
Output: 8
The three periods containing multiple prices have fluctuations 3, 2, and 3. All single-day periods have zero fluctuation.
Example 2
totalPriceFluctuation(prices = [2, 5, 2])
Output: 9
The periods [2, 5], [5, 2], and [2, 5, 2] each have a fluctuation of 3.
Example 3
totalPriceFluctuation(prices = [7, 7, 7])
Output: 0
Every period has the same highest and lowest price, so every fluctuation is zero.