How do you solve Count of Matches in Tournament on LeetCode?

Count of Matches in Tournament (LeetCode #1688) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(1) time complexity and O(1) space complexity. Key insight: Every match results in one team being eliminated.

What is the time complexity of Count of Matches in Tournament?

The optimal solution for Count of Matches in Tournament runs in O(1) time and uses O(1) space. The time complexity is O(1) because we are returning a single calculation without any loops or recursion.

What is the brute force solution for Count of Matches in Tournament?

The brute force approach for Count of Matches in Tournament is Brute Force, with O(n) time complexity and O(1) space complexity. The brute force approach simulates each round of the tournament directly. We repeatedly calculate the number of matches and teams advancing until only one team remains. The optimal Optimal Solution approach improves this to O(1).

What algorithm or data structure is used to solve Count of Matches in Tournament?

Count of Matches in Tournament uses the following concepts: Math, Simulation. The recommended patterns to study are: Mathematical Insight, Simulation.

What are the interview tips for Count of Matches in Tournament?

Always start with a simple brute force approach to understand the problem better. Look for patterns in the problem that can lead to a more efficient solution. Explain your thought process clearly to the interviewer, especially when transitioning from brute force to optimal solutions.

What are common mistakes when solving Count of Matches in Tournament?

Overcomplicating the simulation instead of recognizing the elimination pattern. Forgetting to handle the case of odd teams correctly in the brute force approach.

#1688

Count of Matches in Tournament

Easy

MathSimulationMathematical InsightSimulation

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

💡

Intuition

Time O(1)Space O(1)

The optimal solution recognizes that every match eliminates one team. Thus, the total number of matches is always n - 1, where n is the initial number of teams.

⚙️

Algorithm

1 steps

1Step 1: Return n - 1 directly as the total number of matches.

solution.py2 lines

1def numberOfMatches(n):
2    return n - 1

ℹ

Complexity note: The time complexity is O(1) because we are returning a single calculation without any loops or recursion.

1Every match results in one team being eliminated.
2The total number of matches played is always one less than the number of teams at the start.

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