find all prime numbers in csharp

main.cs
int n = 100;  // we want to find prime numbers up to 100
bool[] primes = new bool[n+1];  // array to store if number is prime, initialized to false

// initialize all numbers as potential prime numbers
for (int i = 2; i <= n; i++)  
{
    primes[i] = true;
}

// iterate from 2 to sqrt(n) and mark all multiples of each prime number as composite numbers
for (int i = 2; i <= Math.Sqrt(n); i++)  
{
    if (primes[i])
    {
        for (int j = i * i; j <= n; j += i)
        {
            primes[j] = false;
        }
    }
}

// print out all prime numbers
for (int i = 2; i <= n; i++)  
{
    if (primes[i])
    {
        Console.Write(i + " ");
    }
}
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