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Count Of Matches In Tournament  Leetcode Solution
LeetCode: Count Of Matches In Tournament Leetcode Solution
Difficulty: Easy
Topics: math simulation
Problem Statement:
You are given an integer n, the number of teams in a tournament that has strange rules:
 If the current number of teams is even, each team gets paired with another team. A total of n / 2 matches are played, and n / 2 teams advance to the next round.
 If the current number of teams is odd, one team randomly advances in the tournament, and the rest gets paired. A total of (n  1) / 2 matches are played, and (n  1) / 2 + 1 teams advance to the next round.
Return the number of matches played in the tournament until a winner is decided.
Solution:
The solution to this problem is pretty straightforward. We can simulate the given tournament and keep track of the total matches played until we get a winner.

If the given number of teams n is even, we can keep dividing it by 2 until we get an odd number. At each step, we will add n / 2 (number of matches played in this round) to the total matches played variable. Finally, when we get an odd number, we can add (n  1) / 2 (number of matches played in the last round) to the total matches played variable and return the total matches played.

If the given number of teams n is odd, we can directly add (n  1) / 2 (number of matches played in the first round) to the total matches played variable. Then we can keep dividing n  1 by 2 until we get 1 team left. At each step, we will add (n  1) / 2 (number of matches played in this round) to the total matches played variable. Finally, we can return the total matches played.
Here's the Python code implementing the above logic:
class Solution:
def numberOfMatches(self, n: int) > int:
matches_played = 0
while n > 1:
if n % 2 == 0:
matches_played += n // 2
n //= 2
else:
matches_played += (n  1) // 2
n = (n  1) // 2 + 1
return matches_played
Time Complexity: O(logn)
Space Complexity: O(1)
We can see that the above solution has a time complexity of O(logn) and a space complexity of O(1). Therefore, this solution is optimal and will pass all the test cases on LeetCode.
Count Of Matches In Tournament Solution Code
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