Breaking News: Grepper is joining You.com. Read the official announcement!

Sieve of Eratosthenes

Add Answer

Curious Caribou answered on July 11, 2021 Popularity 10/10 Helpfulness 2/10

answer Sieve of Eratosthenes

related SieveOfEratosthenes

related Sieve of Eratosthenes

related sieve of eratosthenes

Sieve of Eratosthenes

Comment

int n;
vector<bool> is_prime(n+1, true);
is_prime[0] = is_prime[1] = false;
for (int i = 2; i <= n; i++) {
    if (is_prime[i] && (long long)i * i <= n) {
        for (int j = i * i; j <= n; j += i)
            is_prime[j] = false;
    }
}

Popularity 10/10 Helpfulness 2/10 Language whatever

Source: cp-algorithms.com

Tags: sieve-of-eratosthenes whatever

Link to this answer
Share Copy Link

Contributed on Jan 19 2022

Curious Caribou

0 Answers Avg Quality 2/10

Closely Related Answers

SieveOfEratosthenes

Comments(2)

public static bool[] SieveOfEratosthenes(int num)
{
    bool[] isPrime = new bool[num + 1];
    for (int i = 2; i <= num; i++) isPrime[i] = true;
    // Removing multiples.
    for (int i = 2; i <= num; i++)
    {
        if (isPrime[i])
        {
            for (int j = i * 2; j <= num; j += i) 
            	isPrime[j] = false; // Eliminate multiples of i.                
        }
    }
    return isPrime;
}

Popularity 10/10 Helpfulness 3/10 Language csharp

Source: paiza.io

Tags: c# c

Link to this answer
Share Copy Link

Contributed on Feb 04 2022

PrashantUnity

0 Answers Avg Quality 2/10

Sieve of Eratosthenes

Comment

	boolean[] seiveOfEnthorism(int n) {
        if(n <= 1)
            return new boolean[0];
        boolean prime[] = new boolean[n + 1];
        Arrays.fill(prime, true);
        prime[0] = prime[1] = false;
        int sqr = (int)Math.sqrt(n);
        for(int i = 2; i <= sqr; i++) {
            if(prime[i]) {
                int j = 2;
                while(i * j <= n) {
                    prime[i * j] = false;
                    j++;
                }
            }
        }
        return prime;
    }

Popularity 10/10 Helpfulness 3/10 Language java

Source: Grepper

Tags: java

Link to this answer
Share Copy Link

Contributed on Oct 11 2022

Uptight Unicorn

0 Answers Avg Quality 2/10

sieve of eratosthenes

Comment

internal class Program
{
  public static void Main()
  {
    var n = 53;
    var prime = SieveOfEratosthenes(n);
    for (int i = 2; i <= n; i++)
    {
      if(prime[i] == 0)
      {
        Console.WriteLine(i); ;
      }
    }

  }
  public static int[] SieveOfEratosthenes(int num)
  {
    var isPrime = new int[num + 1];
    for (int i = 2; i <= num; i++)
    {
      if (isPrime[i]==0)
      {
        for (int j = i * 2; j <= num; j += i)
        {
          // Eliminate multiples of i.   
          isPrime[j] = 1;
        }
      }
    }
    return isPrime;
  }
}

Popularity 10/10 Helpfulness 2/10 Language csharp

Source: Grepper

Tags: c# c

Link to this answer
Share Copy Link

Contributed on May 06 2022

PrashantUnity

0 Answers Avg Quality 2/10

sieve of eratosthenes

Comment

function solution(n) {
   const numArr = new Array(n + 1);
   numArr.fill(true);
   numArr[0] = numArr[1] = false;
   for (let i = 2; i <= Math.sqrt(n); i++) {
      for (let j = 2; i * j <= n; j++) {
          numArr[i * j] = false;
      }
   }
   return numArr.filter(Boolean).length;
}

Popularity 10/10 Helpfulness 2/10 Language css

Source: programmers.co.kr

Tags: css

Link to this answer
Share Copy Link

Contributed on Jul 11 2021

Cautious Cockroach

0 Answers Avg Quality 2/10

sieve of eratosthenes

Comment

import java.util.Scanner;

public class BooleanPrimes
{

    public static int counter = 0 ;
    public static void main(String[] argh)
    {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter a number: ");
        int size = scanner.nextInt();
        boolean[] boolArray = new boolean[size+1];
        printArray( generateBoolArray(boolArray,size+1),size);
    }

    public static boolean[] generateBoolArray(boolean[] boolArr, int size) // initializing boolean array with true values
    {
        for (int i = 2; i < size; ++i)
        {
            boolArr[i] = true;
        }
        return chickIfIndexPrime(boolArr, boolArr.length,size);
    }

    public static boolean[] chickIfIndexPrime(boolean[] arrIsPrime, int input, int size)
    {
        int start = 2;
        while (start*start <= input) // first+second loop checking if start is prime
        {
            int i = 2;
            boolean isprime = true;
            while(i*i < start && isprime ) // second loop
            {
                if(start%i == 0)
                {
                    isprime = false;
                }
                ++i;
            }
            if(isprime==true)
            {
                for(int j=4; j<arrIsPrime.length;++j) // third loop checking if the index of the array is prime
                {

                    if(j%start ==0 )
                    {
                        if(j == start)
                        { 
                            ++j;
                            if(j >=arrIsPrime.length)
                            {
                                break;
                            }
                        }
                        arrIsPrime[j]=false;
                    }
                }
            }
            ++start;

        }
        return arrIsPrime;
    }



    public static void printArray(boolean[] arr ,int size){
        System.out.println("The prime numbers from 2 till "+(size));
        int i=0,j = 0 ;
        while(i<arr.length){
            if ( arr[i] == true ) {
                System.out.print(i+" ");
                ++counter;

            }
            ++i;
        }

        System.out.println();
        System.out.println("\nIn total there is "+counter+" prime numbers");

    }

}

Popularity 10/10 Helpfulness 1/10 Language java

Source: Grepper

Tags: java

Link to this answer
Share Copy Link

Contributed on Aug 06 2021

Mero

0 Answers Avg Quality 2/10

Sieve of Eratosthenes

Contents

More Related Answers

Sieve of Eratosthenes

Closely Related Answers

SieveOfEratosthenes

Sieve of Eratosthenes

sieve of eratosthenes

sieve of eratosthenes

sieve of eratosthenes

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.