A tournament features 128 teams, and each match is a knockout match.

using System;

class Tournament
{
public static void Main()
{
int totalTeams = 128; // Initial number of teams
int totalMatches = totalTeams - 1; // Number of matches = teams - 1

    Console.WriteLine("Total matches played in the tournament: " + totalMatches);
    // Simulate the rounds
    int round = 1;
    int teamsInCurrentRound = totalTeams;
    while (teamsInCurrentRound > 1)
    {
        int matchesInCurrentRound =                     teamsInCurrentRound / 2;
        Console.WriteLine($"Round {round}: {matchesInCurrentRound} matches");
        // Half of the teams are eliminated in each round
        teamsInCurrentRound /= 2;
        round++;
    }
}

}

Example Output:
Total matches played in the tournament: 127
Round 1: 64 matches
Round 2: 32 matches
Round 3: 16 matches
Round 4: 8 matches
Round 5: 4 matches
Round 6: 2 matches
Round 7: 1 matches