1688. Count of Matches in Tournament

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Problem

You are given an integer n, the number of teams in a tournament that has strange rules:

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:

Solution

/**
 * @param {number} n
 * @return {number}
 */
var numberOfMatches = function(n) {
    if (n === 1) return 0;
    if (n % 2) {
        return Math.floor(n / 2) + numberOfMatches((n + 1) / 2);
    } else {
        return (n / 2) + numberOfMatches(n / 2);
    }
};

Explain:

nope.

Complexity: