1688 Count of Matches in Tournament - Easy
Problem:
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, andn / 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.
Example 1:
Input: n = 7 Output: 6 Explanation: Details of the tournament:
- 1st Round: Teams = 7, Matches = 3, and 4 teams advance.
- 2nd Round: Teams = 4, Matches = 2, and 2 teams advance.
- 3rd Round: Teams = 2, Matches = 1, and 1 team is declared the winner. Total number of matches = 3 + 2 + 1 = 6.
Example 2:
Input: n = 14 Output: 13 Explanation: Details of the tournament:
- 1st Round: Teams = 14, Matches = 7, and 7 teams advance.
- 2nd Round: Teams = 7, Matches = 3, and 4 teams advance.
- 3rd Round: Teams = 4, Matches = 2, and 2 teams advance.
- 4th Round: Teams = 2, Matches = 1, and 1 team is declared the winner. Total number of matches = 7 + 3 + 2 + 1 = 13.
Constraints:
1 <= n <= 200
Problem Analysis:
-
Since there are
n
teams in the tournament, there is only 1 final winner, son-1
team have to be eliminated. -
Time Complexity: O(1)
-
Space Complexity: O(1)
Solutions:
class Solution:
def numberOfMatches(self, n: int) -> int:
return n-1