Count of Matches in Tournament LeetCode solution in Java

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class Solution {
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  public int numberOfMatches(int n) {
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    // This is the problem's base case; we know that if n == 1,
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    // the number of matches played must be 0, since the last team left
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    // can't play a match against themselves.
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    if (n == 1) return 0;
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    // We declare an int to hold our recursive solution.
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    int res;
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    // We initialize res using a recursive call, reducing n
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    // as described in the problem.
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    if (n % 2 == 0) {
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      res = numberOfMatches(n / 2);
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      // After the recursive call is executed, we add the appropriate value to
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      // our solution variable.
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      res += n / 2;
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    } else {
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      res = numberOfMatches((n - 1) / 2 + 1);
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      res += (n - 1) / 2;
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    }
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    // Our initial call to numberOfMatches()
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    // will return the total number of matches
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    // added to res in each recursive call.
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    return res;
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  }
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}