从给定数组中删除所有素数

给定N个整数的数组arr [] ，任务是删除所有素数。

例子：

Input: arr[] = {4, 6, 5, 3, 8, 7, 10, 11, 14, 15}
Output: 4 6 8 10 14 15

Input: arr[] = {2, 4, 7, 8, 9, 11}
Output: 4 8 9

方法：遍历数组并检查当前数是否为质数，然后左移其后的所有元素以删除该质数并减小数组长度的值。对数组的所有元素重复此操作。要检查数字是否为素数，请使用Eratosthenes筛子生成所有素数。

下面是上述方法的实现：

C++

// C++ implementation of the approach
#include 
using namespace std;
  
const int sz = 1e5;
bool isPrime[sz + 1];
  
// Function for Sieve of Eratosthenes
void sieve()
{
    memset(isPrime, true, sizeof(isPrime));
  
    isPrime[0] = isPrime[1] = false;
  
    for (int i = 2; i * i <= sz; i++) {
        if (isPrime[i]) {
            for (int j = i * i; j < sz; j += i) {
                isPrime[j] = false;
            }
        }
    }
}
  
// Function to print the elements of the array
void printArray(int arr[], int len)
{
    for (int i = 0; i < len; i++) {
        cout << arr[i] << ' ';
    }
}
  
// Function to remove all the prime numbers
void removePrimes(int arr[], int len)
{
    // Generate primes
    sieve();
  
    // Traverse the array
    for (int i = 0; i < len; i++) {
  
        // If the current element is prime
        if (isPrime[arr[i]]) {
  
            // Shift all the elements on the
            // right of it to the left
            for (int j = i; j < len; j++) {
                arr[j] = arr[j + 1];
            }
  
            // Decrease the loop counter by 1
            // to check the shifted element
            i--;
  
            // Decrease the length
            len--;
        }
    }
  
    // Print the updated array
    printArray(arr, len);
}
  
// Driver code
int main()
{
    int arr[] = { 4, 6, 5, 3, 8, 7,
                  10, 11, 14, 15 };
    int len = sizeof(arr) / sizeof(int);
  
    removePrimes(arr, len);
  
    return 0;
}

Java

// Java implementation of the approach
class GFG
{
static int sz = (int) 1e5;
static boolean []isPrime = new boolean[sz + 1];
  
// Function for Sieve of Eratosthenes
static void sieve()
{
    for (int i = 0; i < sz + 1; i++)
        isPrime[i] = true;
      
    isPrime[0] = isPrime[1] = false;
  
    for (int i = 2; i * i <= sz; i++) 
    {
        if (isPrime[i]) 
        {
            for (int j = i * i; j < sz; j += i) 
            {
                isPrime[j] = false;
            }
        }
    }
}
  
// Function to print the elements of the array
static void printArray(int arr[], int len)
{
    for (int i = 0; i < len; i++) 
    {
        System.out.print(arr[i] + " ");
    }
}
  
// Function to remove all the prime numbers
static void removePrimes(int arr[], int len)
{
    // Generate primes
    sieve();
  
    // Traverse the array
    for (int i = 0; i < len; i++) 
    {
  
        // If the current element is prime
        if (isPrime[arr[i]]) 
        {
  
            // Shift all the elements on the
            // right of it to the left
            for (int j = i; j < len-1; j++)
            {
                arr[j] = arr[j + 1];
            }
  
            // Decrease the loop counter by 1
            // to check the shifted element
            i--;
  
            // Decrease the length
            len--;
        }
    }
  
    // Print the updated array
    printArray(arr, len);
}
  
// Driver code
public static void main(String[] args)
{
    int arr[] = { 4, 6, 5, 3, 8, 7,
                  10, 11, 14, 15 };
    int len = arr.length;
  
    removePrimes(arr, len);
}
}
   
// This code is contributed by PrinciRaj1992

Python3

# Python3 implementation of the approach
sz = 10**5
isPrime = [True for i in range(sz + 1)]
  
# Function for Sieve of Eratosthenes
def sieve():
      
    isPrime[0] = isPrime[1] = False
  
    i = 2
    while i * i < sz:
        if (isPrime[i]):
            for j in range(i * i, sz, i):
                isPrime[j] = False
        i += 1
  
# Function to pr the elements of the array
def prArray(arr, lenn):
    for i in range(lenn):
        print(arr[i], end = " ")
  
# Function to remove all the prime numbers
def removePrimes(arr, lenn):
      
    # Generate primes
    sieve()
  
    # Traverse the array
    i = 0
    while i < lenn:
  
        # If the current element is prime
        if (isPrime[arr[i]]):
  
            # Shift all the elements on the
            # right of it to the left
            for j in range(i, lenn - 1):
                arr[j] = arr[j + 1]
  
            # Decrease the loop counter by 1
            # to check the shifted element
            i -= 1
  
            # Decrease the lenngth
            lenn -= 1
  
        i += 1
  
    # Pr the updated array
    prArray(arr, lenn)
  
# Driver code
if __name__ == '__main__':
    arr = [4, 6, 5, 3, 8, 7, 10, 11, 14, 15]
    lenn = len(arr)
  
    removePrimes(arr, lenn)
  
# This code is contributed by Mohit Kumar

C#

// C# implementation of the approach
using System;
  
class GFG
{
static int sz = (int) 1e5;
static bool []isPrime = new bool[sz + 1];
  
// Function for Sieve of Eratosthenes
static void sieve()
{
    for (int i = 0; i < sz + 1; i++)
        isPrime[i] = true;
      
    isPrime[0] = isPrime[1] = false;
  
    for (int i = 2; i * i <= sz; i++) 
    {
        if (isPrime[i]) 
        {
            for (int j = i * i;
                     j < sz; j += i) 
            {
                isPrime[j] = false;
            }
        }
    }
}
  
// Function to print the elements
// of the array
static void printArray(int []arr, 
                       int len)
{
    for (int i = 0; i < len; i++) 
    {
        Console.Write(arr[i] + " ");
    }
}
  
// Function to remove
// all the prime numbers
static void removePrimes(int []arr,
                         int len)
{
    // Generate primes
    sieve();
  
    // Traverse the array
    for (int i = 0; i < len; i++) 
    {
  
        // If the current element is prime
        if (isPrime[arr[i]]) 
        {
  
            // Shift all the elements on the
            // right of it to the left
            for (int j = i; j < len - 1; j++)
            {
                arr[j] = arr[j + 1];
            }
  
            // Decrease the loop counter by 1
            // to check the shifted element
            i--;
  
            // Decrease the length
            len--;
        }
    }
  
    // Print the updated array
    printArray(arr, len);
}
  
// Driver code
public static void Main(String[] args)
{
    int []arr = { 4, 6, 5, 3, 8, 7,
                 10, 11, 14, 15 };
    int len = arr.Length;
  
    removePrimes(arr, len);
}
}
  
// This code is contributed by PrinciRaj1992

输出：

4 6 8 10 14 15