We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Prepare
  2. Tutorials
  3. 30 Days of Code
  4. Day 25: Running Time and Complexity
  5. Discussions

Day 25: Running Time and Complexity

Sort by

recency

|

812 Discussions

|

  • h2400033083
     + 0 comments

    include

    include

    const char* is_prime(int n) { if (n <= 1) { return "Not prime"; } if (n <= 3) { return "Prime"; } if (n % 2 == 0 || n % 3 == 0) { return "Not prime"; }

    // Check for divisibility from 5 to sqrt(n)
for (int i = 5; i * i <= n; i += 6) {
    if (n % i == 0 || n % (i + 2) == 0) {
        return "Not prime";
    }
}
return "Prime";

    }

    int main() { int n; printf("Enter a number: "); scanf("%d", &n);

    printf("%s\n", is_prime(n));

        return 0; }

  • vdinesh7030
     + 0 comments

    t=int(input()) for _ in range(t): n=int(input()) if n<=1: print('Not prime') else: for i in range(2,int(n**0.5)+1): if(n%i)==0: print('Not prime') break else: print('Prime')

  • destriegieta
     + 0 comments

    javaScript Solution

    function processData(input) { const numbers = input.split('\n').slice(1).map(Number);

    numbers.forEach(number => { console.log(isPrime(number) ? 'Prime' : 'Not prime'); }); }

    function isPrime(num) { if (num <= 1) return false; if (num <= 3) return true; if (num % 2 === 0 || num % 3 === 0) return false;

    for (let i = 5; i * i <= num; i += 6) { if (num % i === 0 || num % (i + 2) === 0) return false; }

    return true; } `

  • syed_imraan92
     + 0 comments
    C# Csharp

    static void Main(String[] args) 
    {
        int row = int.TryParse(Console.ReadLine(), out int inputRow) ? inputRow : 0;

        while (row > 0)
        {
            int.TryParse(Console.ReadLine(), out int rec);

            if (rec > 1)
            {
                bool isPrime = true;

                // Optimized primality test: check divisors only up to the square root
                for (int i = 2; i * i <= rec; i++)
                {
                    if (rec % i == 0)
                    {
                        isPrime = false;
                        break;
                    }
                }

                string result = isPrime ? "Prime" : "Not prime";
                Console.WriteLine(result);
            }
            else
            {
                Console.WriteLine("Not prime");
            }

            row--;
        }
    }

  • illogicalsleepi1
     + 0 comments
    def isprime(p):
    if p <= 1:
        return 'Not prime'
    if p <= 3:
        return 'Prime'
    if p % 2 == 0 or p % 3 == 0:
        return 'Not prime'
    i = 5
    while i * i <= p:
        if p % i == 0 or p % (i + 2) == 0:
            return 'Not prime'
        i += 6
    return 'Prime'

x = int(input())
for _ in range(x):
    p = int(input())
    print(isprime(p))