Maximum Profitable Triplets With Increasing Prices II(LeetCode 2921):

Problem

Given the 0-indexed arrays prices and profits of length n. There are n items in an store where the ith item has a price of prices[i] and a profit of profits[i].

We have to pick three items with the following condition:

  • prices[i] < prices[j] < prices[k] where i < j < k.

If we pick items with indices i, j and k satisfying the above condition, the profit would be profits[i] + profits[j] + profits[k].

Return the maximum profit we can get, and -1 if it's not possible to pick three items with the given condition.

 

Example 1:

Input: prices = [10,2,3,4], profits = [100,2,7,10]
Output: 19
Explanation: We can't pick the item with index i=0 since there are no indices j and k such that the condition holds.
So the only triplet we can pick, are the items with indices 1, 2 and 3 and it's a valid pick since prices[1] < prices[2] < prices[3].
The answer would be sum of their profits which is 2 + 7 + 10 = 19.

Example 2:

Input: prices = [1,2,3,4,5], profits = [1,5,3,4,6]
Output: 15
Explanation: We can select any triplet of items since for each triplet of indices i, j and k such that i < j < k, the condition holds.
Therefore the maximum profit we can get would be the 3 most profitable items which are indices 1, 3 and 4.
The answer would be sum of their profits which is 5 + 4 + 6 = 15.

Example 3:

Input: prices = [4,3,2,1], profits = [33,20,19,87]
Output: -1
Explanation: We can't select any triplet of indices such that the condition holds, so we return -1.

 

Constraints:

  • 3 <= prices.length == profits.length <= 50000
  • 1 <= prices[i] <= 5000
  • 1 <= profits[i] <= 106