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sieve of eratosthenes

C#

/* Sieve of Erastosthenes in C#
 * Written by Robert Hoelz
 *
 * If you're using Mono, use gmcs to compile.
 */

using System;
using System.Collections.Generic;

class Sieve {
    private List<int> primes;

    public Sieve(string str) {
        int limit = System.Convert.ToInt32(str);
        primes = new List<int>();

        primes.Add(0);
        primes.Add(0);

        for(int i = 2; i < limit; i++) {
            primes.Add(1);
        }
    }

    private void generate() {
        int currPrime = 2;

        while(currPrime * currPrime < primes.Count) {
            int currMult = 2;

            while((currMult * currPrime) < primes.Count) {
                primes[currMult * currPrime] = 0;
                currMult++;
            }
            int i;
            for(i = currPrime + 1; i < primes.Count; i++) {
                if(primes[i] == 1)
                    break;
            }
            currPrime = i;
        }
    }

    private void print() {
        for(int i = 0; i < primes.Count; i++) {
            if(primes[i] == 1)
                Console.Write(i + " ");
        }
        Console.WriteLine();
    }

    public static void Main(string[] args) {
        if(args.Length > 0) {
            Sieve s = new Sieve(args[0]);
            s.generate();
            s.print();
        }
    }
}

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