How do you solve Merge Triplets to Form Target Triplet on LeetCode?

Merge Triplets to Form Target Triplet (LeetCode #1899) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: We only care about triplets that can contribute to the target values.

What is the brute force solution for Merge Triplets to Form Target Triplet?

The brute force approach for Merge Triplets to Form Target Triplet is Brute Force, with O(n²) time complexity and O(1) space complexity. We can check all possible pairs of triplets and see if we can form the target triplet by taking the maximum values. This is a straightforward approach but can be inefficient. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Merge Triplets to Form Target Triplet?

Merge Triplets to Form Target Triplet uses the following concepts: Array, Greedy. The recommended patterns to study are: Greedy, Array.

What are the interview tips for Merge Triplets to Form Target Triplet?

Always clarify the problem constraints and what operations are allowed. Think about edge cases, such as empty triplet arrays or triplets that cannot contribute to the target. Explain your thought process clearly; it shows your understanding of the problem.

What are common mistakes when solving Merge Triplets to Form Target Triplet?

Failing to check if the triplet values exceed the target values. Assuming that any combination of triplets can form the target without checking individual contributions.

#1899

Merge Triplets to Form Target Triplet

Medium

ArrayGreedyGreedyArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(1)

💡

Intuition

Time O(n)Space O(1)

Instead of checking all pairs, we can directly find the maximum values from the triplets and check if they match the target. This is more efficient and avoids unnecessary comparisons.

⚙️

Algorithm

3 steps

1Step 1: Initialize max_a, max_b, and max_c to 0.
2Step 2: Iterate through each triplet and update max_a, max_b, and max_c with the maximum values found in the triplets that do not exceed the target values.
3Step 3: After processing all triplets, check if max_a equals target[0], max_b equals target[1], and max_c equals target[2]. If they match, return true; otherwise, return false.

solution.py10 lines

1# Full working Python code
2
3def mergeTriplets(triplets, target):
4    max_a, max_b, max_c = 0, 0, 0
5    for a, b, c in triplets:
6        if a <= target[0] and b <= target[1] and c <= target[2]:
7            max_a = max(max_a, a)
8            max_b = max(max_b, b)
9            max_c = max(max_c, c)
10    return max_a == target[0] and max_b == target[1] and max_c == target[2]

ℹ

Complexity note: The time complexity is O(n) since we only need to iterate through the triplets once. The space complexity is O(1) because we are using a fixed amount of extra space.

1We only care about triplets that can contribute to the target values.
2The maximum values from the triplets must match the target values exactly.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.