Merge Triplets to Form Target Triplet

Merge Triplets to Form Target Triplet is a Medium Data Structures and Algorithms interview problem you can solve, run and submit on Thita.ai. It belongs to the Greedy Patterns pattern, in the Sorting Based subpattern.

Problem statement

You are given triplets, a list of triplets, where each triplet is an array of three integers. You are also given target, another three-integer array. A triplet's first, second, and third positions are treated independently as coordinates.

You may select any collection of triplets and merge them. Merging takes the maximum value at each coordinate across all selected triplets; for instance, the merged first coordinate is the largest first coordinate among the selected triplets. A triplet may be selected at most once, and the selected collection may contain one or more triplets.

Return true if some selection of triplets can be merged to produce exactly target; otherwise, return false. No coordinate of a selected triplet may exceed the corresponding coordinate of target, because merging uses coordinate-wise maximums.

Example 1:

Input: triplets = [[2,4,1],[1,3,5],[2,3,4]], target = [2,4,5] Output: true Explanation: The first two triplets are individually no larger than the target. Their coordinate-wise maximum is [2,4,5], so the target can be formed.

Example 2:

Input: triplets = [[4,1,2],[2,5,2],[3,2,6]], target = [3,5,2] Output: false Explanation: The first triplet exceeds the target in its first coordinate, and the third exceeds it in its third coordinate. The only remaining triplet cannot provide the target's first coordinate.

Example 3:

Input: triplets = [[1,2,3],[2,1,2],[1,2,2]], target = [2,2,3] Output: true Explanation: The first triplet supplies the third coordinate and the second triplet supplies the first; together their maximum is [2,2,3].

Constraints:

- 1 <= triplets.length <= 10^5 - triplets[i].length = 3 for every valid index i - 1 <= triplets[i][j] <= 10^3 for every valid index i and coordinate j - target.length = 3 - 1 <= target[j] <= 10^3 for every coordinate j

Topics and companies

Topics: Array, Greedy, Iteration.

How to practise Merge Triplets to Form Target Triplet on Thita.ai

Starter code is provided in C#, C++, Go, Java, JavaScript and Python. Your solution runs against 5 test cases for this problem, with the AI coach available for a hint when you are stuck rather than a finished answer. The reference solution runs in O(n), where n is triplets.size(). time and O(1), excluding the input storage. space.

Open Merge Triplets to Form Target Triplet in the code editor, or read the Merge Triplets to Form Target Triplet editorial for a worked solution with its approach and complexity analysis.

Where Merge Triplets to Form Target Triplet sits in the DSA pattern sheet

Problems related to Merge Triplets to Form Target Triplet

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