Dado un número n, imprima todos los números primos menores o iguales que n. También se da que n es un número pequeño.
Ejemplo:
C++
// C++ program to print all primes smaller than or equal to
// n using Sieve of Eratosthenes
#include <bits/stdc++.h>
using namespace std;
void SieveOfEratosthenes(int n)
{
// Create a boolean array "prime[0..n]" and initialize
// all entries it as true. A value in prime[i] will
// finally be false if i is Not a prime, else true.
bool prime[n + 1];
memset(prime, true, sizeof(prime));
for (int p = 2; p * p <= n; p++) {
// If prime[p] is not changed, then it is a prime
if (prime[p] == true) {
// Update all multiples of p greater than or
// equal to the square of it numbers which are
// multiple of p and are less than p^2 are
// already been marked.
for (int i = p * p; i <= n; i += p)
prime[i] = false;
}
}
// Print all prime numbers
for (int p = 2; p <= n; p++)
if (prime[p])
cout << p << " ";
}
// Driver Code
int main()
{
int n = 30;
cout << "Following are the prime numbers smaller "
<< " than or equal to " << n << endl;
SieveOfEratosthenes(n);
return 0;
}
C
// C program to print all primes smaller than or equal to
// n using Sieve of Eratosthenes
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
void SieveOfEratosthenes(int n)
{
// Create a boolean array "prime[0..n]" and initialize
// all entries it as true. A value in prime[i] will
// finally be false if i is Not a prime, else true.
bool prime[n + 1];
memset(prime, true, sizeof(prime));
for (int p = 2; p * p <= n; p++) {
// If prime[p] is not changed, then it is a prime
if (prime[p] == true) {
// Update all multiples of p greater than or
// equal to the square of it numbers which are
// multiple of p and are less than p^2 are
// already been marked.
for (int i = p * p; i <= n; i += p)
prime[i] = false;
}
}
// Print all prime numbers
for (int p = 2; p <= n; p++)
if (prime[p])
printf("%d ",p);
}
// Driver Code
int main()
{
int n = 30;
printf("Following are the prime numbers smaller than or equal to %d \n", n);
SieveOfEratosthenes(n);
return 0;
}
// This code is contributed by Aditya Kumar (adityakumar129)
Java
// Java program to print all primes smaller than or equal to
// n using Sieve of Eratosthenes
class SieveOfEratosthenes {
void sieveOfEratosthenes(int n)
{
// Create a boolean array "prime[0..n]" and
// initialize all entries it as true. A value in
// prime[i] will finally be false if i is Not a
// prime, else true.
boolean prime[] = new boolean[n + 1];
for (int i = 0; i <= n; i++)
prime[i] = true;
for (int p = 2; p * p <= n; p++) {
// If prime[p] is not changed, then it is a
// prime
if (prime[p] == true) {
// Update all multiples of p greater than or
// equal to the square of it numbers which
// are multiple of p and are less than p^2
// are already been marked.
for (int i = p * p; i <= n; i += p)
prime[i] = false;
}
}
// Print all prime numbers
for (int i = 2; i <= n; i++) {
if (prime[i] == true)
System.out.print(i + " ");
}
}
// Driver Code
public static void main(String args[])
{
int n = 30;
System.out.print("Following are the prime numbers ");
System.out.println("smaller than or equal to " + n);
SieveOfEratosthenes g = new SieveOfEratosthenes();
g.sieveOfEratosthenes(n);
}
}
// This code is contributed by Aditya Kumar (adityakumar129)
Python3
# Python program to print all
# primes smaller than or equal to
# n using Sieve of Eratosthenes
def SieveOfEratosthenes(n):
# Create a boolean array
# "prime[0..n]" and initialize
# all entries it as true.
# A value in prime[i] will
# finally be false if i is
# Not a prime, else true.
prime = [True for i in range(n+1)]
p = 2
while (p * p <= n):
# If prime[p] is not
# changed, then it is a prime
if (prime[p] == True):
# Update all multiples of p
for i in range(p * p, n+1, p):
prime[i] = False
p += 1
# Print all prime numbers
for p in range(2, n+1):
if prime[p]:
print(p)
# Driver code
if __name__ == '__main__':
n = 20
print("Following are the prime numbers smaller"),
print("than or equal to", n)
SieveOfEratosthenes(n)
C#
// C# program to print all primes
// smaller than or equal to n
// using Sieve of Eratosthenes
using System;
namespace prime {
public class GFG {
public static void SieveOfEratosthenes(int n)
{
// Create a boolean array
// "prime[0..n]" and
// initialize all entries
// it as true. A value in
// prime[i] will finally be
// false if i is Not a
// prime, else true.
bool[] prime = new bool[n + 1];
for (int i = 0; i <= n; i++)
prime[i] = true;
for (int p = 2; p * p <= n; p++)
{
// If prime[p] is not changed,
// then it is a prime
if (prime[p] == true)
{
// Update all multiples of p
for (int i = p * p; i <= n; i += p)
prime[i] = false;
}
}
// Print all prime numbers
for (int i = 2; i <= n; i++)
{
if (prime[i] == true)
Console.Write(i + " ");
}
}
// Driver Code
public static void Main()
{
int n = 30;
Console.WriteLine(
"Following are the prime numbers");
Console.WriteLine("smaller than or equal to " + n);
SieveOfEratosthenes(n);
}
}
}
// This code is contributed by Sam007.
PHP
<?php
// php program to print all primes smaller
// than or equal to n using Sieve of
// Eratosthenes
function SieveOfEratosthenes($n)
{
// Create a boolean array "prime[0..n]"
// and initialize all entries it as true.
// A value in prime[i] will finally be
// false if i is Not a prime, else true.
$prime = array_fill(0, $n+1, true);
for ($p = 2; $p*$p <= $n; $p++)
{
// If prime[p] is not changed,
// then it is a prime
if ($prime[$p] == true)
{
// Update all multiples of p
for ($i = $p*$p; $i <= $n; $i += $p)
$prime[$i] = false;
}
}
// Print all prime numbers
for ($p = 2; $p <= $n; $p++)
if ($prime[$p])
echo $p." ";
}
// Driver Code
$n = 30;
echo "Following are the prime numbers "
."smaller than or equal to " .$n."\n" ;
SieveOfEratosthenes($n);
// This code is contributed by mits
?>
Javascript
<script>
// javascript program to print all
// primes smaller than or equal to
// n using Sieve of Eratosthenes
function sieveOfEratosthenes(n)
{
// Create a boolean array
// "prime[0..n]" and
// initialize all entries
// it as true. A value in
// prime[i] will finally be
// false if i is Not a
// prime, else true.
prime = Array.from({length: n+1}, (_, i) => true);
for (p = 2; p * p <= n; p++)
{
// If prime[p] is not changed, then it is a
// prime
if (prime[p] == true)
{
// Update all multiples of p
for (i = p * p; i <= n; i += p)
prime[i] = false;
}
}
// Print all prime numbers
for (i = 2; i <= n; i++)
{
if (prime[i] == true)
document.write(i + " ");
}
}
// Driver Code
var n = 30;
document.write(
"Following are the prime numbers ");
document.write("smaller than or equal to " + n+"<br>");
sieveOfEratosthenes(n);
// This code is contributed by 29AjayKumar
</script>
C++
// the following implementation
// stores only halves of odd numbers
// the algorithm is a faster by some constant factors
#include <bitset>
#include <iostream>
using namespace std;
bitset<500001> Primes;
void SieveOfEratosthenes(int n)
{
Primes[0] = 1;
for (int i = 3; i*i <= n; i += 2) {
if (Primes[i / 2] == 0) {
for (int j = 3 * i; j <= n; j += 2 * i)
Primes[j / 2] = 1;
}
}
}
int main()
{
int n = 100;
SieveOfEratosthenes(n);
for (int i = 1; i <= n; i++) {
if (i == 2)
cout << i << ' ';
else if (i % 2 == 1 && Primes[i / 2] == 0)
cout << i << ' ';
}
return 0;
}
Java
// Java program for the above approach
import java.io.*;
public class GFG {
static int[] Primes = new int[500001];
static void SieveOfEratosthenes(int n)
{
Primes[0] = 1;
for (int i = 3; i * i <= n; i += 2) {
if (Primes[i / 2] == 0) {
for (int j = 3 * i; j <= n; j += 2 * i)
Primes[j / 2] = 1;
}
}
}
// Driver Code
public static void main(String[] args)
{
int n = 100;
SieveOfEratosthenes(n);
for (int i = 1; i <= n; i++) {
if (i == 2)
System.out.print(i + " ");
else if (i % 2 == 1 && Primes[i / 2] == 0)
System.out.print(i + " ");
}
}
}
// This code is contributed by ukasp.
Python3
# Python program for the above approach Primes = [0] * 500001 def SieveOfEratosthenes(n) : Primes[0] = 1 i = 3 while(i*i <= n) : if (Primes[i // 2] == 0) : for j in range(3 * i, n+1, 2 * i) : Primes[j // 2] = 1 i += 2 # Driver Code if __name__ == "__main__": n = 100 SieveOfEratosthenes(n) for i in range(1, n+1) : if (i == 2) : print( i, end = " ") elif (i % 2 == 1 and Primes[i // 2] == 0) : print( i, end = " ") # This code is contributed by code_hunt.
C#
// C# program for the above approach
using System;
public class GFG {
static int[] Primes = new int[500001];
static void SieveOfEratosthenes(int n)
{
Primes[0] = 1;
for (int i = 3; i*i <= n; i += 2) {
if (Primes[i / 2] == 0) {
for (int j = 3 * i; j <= n; j += 2 * i)
Primes[j / 2] = 1;
}
}
}
// Driver Code
public static void Main(String[] args) {
int n = 100;
SieveOfEratosthenes(n);
for (int i = 1; i <= n; i++) {
if (i == 2)
Console.Write(i + " ");
else if (i % 2 == 1 && Primes[i / 2] == 0)
Console.Write(i + " ");
}
}
}
// This code is contributed by sanjoy_62.
Javascript
// A JavaScript Program
// the following implementation
// stores only halves of odd numbers
// the algorithm is a faster by some constant factors
let Primes = new Array(500001).fill(0);
function SieveOfEratosthenes(n)
{
Primes[0] = 1;
for (let i = 3; i*i <= n; i += 2) {
if (Primes[Math.floor(i / 2)] == 0) {
for (let j = 3 * i; j <= n; j += 2 * i){
Primes[Math.floor(j / 2)] = 1;
}
}
}
}
let n = 100;
SieveOfEratosthenes(n);
let res = "";
for (let i = 1; i <= n; i++) {
if (i == 2){
res = res + i + " ";
}
else if (i % 2 == 1 && Primes[Math.floor(i / 2)] == 0){
res = res + i + " ";
}
}
console.log(res);
// The code is contributed by Gautam goel (gautamgoel962)
Publicación traducida automáticamente
Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA