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Maximum Value of an Ordered Triplet I - LeetCode 2873 Solution

Maximum Value of an Ordered Triplet I - Complete Solution Guide

Maximum Value of an Ordered Triplet I is LeetCode problem 2873, a Easy level challenge. This complete guide provides step-by-step explanations, multiple solution approaches, and optimized code in python3, java, cpp, c.

Problem Statement

You are given a 0-indexed integer array nums . Return the maximum value over all triplets of indices (i, j, k) such that i < j < k . If all such triplets have a negative value, return 0 . The value of a triplet of indices (i, j, k) is equal to (nums[i] - nums[j]) * nums[k] . Example 1: Input: nums = [12,6,1,2,7] Output: 77 Explanation: The value of the triplet (0, 2, 4) is (nums[0] - nums[2]) * nums[4] = 77. It can be shown that there are no ordered triplets of indices with a value greater than

Detailed Explanation

The problem asks you to find the maximum value among all possible triplets (i, j, k) from a given array `nums`, where i < j < k. The value of a triplet is calculated as (nums[i] - nums[j]) * nums[k]. If all triplet values are negative, the function should return 0. The input is a 0-indexed integer array, and the output is a single integer representing the maximum triplet value.

Solution Approach

The provided code uses a brute-force approach. It iterates through all possible combinations of indices (i, j, k) such that i < j < k. For each triplet, it calculates the triplet value and updates the `max_value` if a larger value is found. Finally, it returns the `max_value`.

Step-by-Step Algorithm

  1. Initialize `max_value` to 0.
  2. Iterate through the array using three nested loops to generate all possible triplets (i, j, k) where i < j < k.
  3. For each triplet, calculate the value: `(nums[i] - nums[j]) * nums[k]`. Ensure that the calculation is performed with a data type that can handle potential overflows (e.g., `long long` in C++).
  4. Update `max_value` if the calculated value is greater than the current `max_value`.
  5. After checking all triplets, return `max_value`.

Key Insights

  • The brute-force approach of checking all possible triplets is straightforward but might be inefficient for larger arrays.
  • No specific data structure is needed beyond iterating through the array. The problem can be solved using nested loops.
  • The problem requires careful handling of potential integer overflow when multiplying numbers. Using a `long long` (or equivalent) data type helps prevent this.

Complexity Analysis

Time Complexity: O(n^3)

Space Complexity: O(1)

Topics

This problem involves: Array.

Companies

Asked at: Media.net.