使用自定义比较器对数组中的奇数和偶数进行排序和分离

给定一个包含N个元素的数组arr[] ，任务是使用自定义比较器对数组中的奇数和偶数进行排序和分离。

例子：

Input: arr[] = { 5, 3, 2, 8, 7, 4, 6, 9, 1 }
Output: 2 4 6 8 1 3 5 7 9

Input: arr[] = { 12, 15, 6, 2, 7, 13, 9, 4 }
Output: 2 4 6 12 7 9 13 15

方法：我们知道 std::sort() 用于按升序排序，但我们可以使用自定义比较器操作 sort() 以进行某些特定排序。
现在，为了将它们分开，可以使用的属性是偶数的最后一位为 0，奇数为 1。因此，使用自定义比较器根据最后一位对元素进行排序数字。

下面是上述方法的实现：

C++

// C++ program for the above approach
 
#include 
using namespace std;
 
// Creating custom comparator
bool compare(int a, int b)
{
 
    // If both are odd or even
    // then sorting in increasing order
    if ((a & 1) == (b & 1)) {
        return a < b;
    }
 
    // Sorting on the basis of last bit if
    // if one is odd and the other one is even
    return (a & 1) < (b & 1);
}
 
// Function to
void separateOddEven(int* arr, int N)
{
    // Separating them using sort comparator
    sort(arr, arr + N, compare);
 
    for (int i = 0; i < N; ++i) {
        cout << arr[i] << ' ';
    }
}
 
// Driver Code
int main()
{
    int arr[] = { 12, 15, 6, 2, 7, 13, 9, 4 };
    int N = sizeof(arr) / sizeof(int);
    separateOddEven(arr, N);
}

Java

// Java program for the above approach
import java.util.*;
 
class GFG{
 
// Creating custom comparator
static boolean comparecust(Integer a, Integer b)
{
 
    // If both are odd or even
    // then sorting in increasing order
    if ((a & 1) == (b & 1)) {
        return a < b;
    }
 
    // Sorting on the basis of last bit if
    // if one is odd and the other one is even
    return (a & 1) < (b & 1);
}
 
// Function to
static void separateOddEven(Integer []arr, int N)
{
    // Separating them using sort comparator
    Arrays.sort(arr, new Comparator() {
 
        @Override
        public int compare(Integer a, Integer b) {
            // If both are odd or even
            // then sorting in increasing order
            if ((a & 1) == (b & 1)) {
                return a < b?-1:1;
            }
 
            // Sorting on the basis of last bit if
            // if one is odd and the other one is even
            return ((a & 1) < (b & 1))?-1:1;
        }
         
    });
 
    for (int i = 0; i < N; ++i) {
        System.out.print(arr[i] +" ");
    }
}
 
// Driver Code
public static void main(String[] args)
{
    Integer arr[] = { 12, 15, 6, 2, 7, 13, 9, 4 };
    int N = arr.length;
    separateOddEven(arr, N);
}
}
 
// This code is contributed by 29AjayKumar

C#

// C# program for the above approach
using System;
using System.Collections;
 
class compare : IComparer
{
     
    // Call CaseInsensitiveComparer.Compare
    public int Compare(Object x, Object y)
    {
        int a = (int)x;
        int b = (int)y;
         
        // If both are odd or even
        // then sorting in increasing order
        if ((a & 1) == (b & 1))
        {
            return a < b ? -1 : 1;
        }
 
        // Sorting on the basis of last bit if
        // if one is odd and the other one is even
        return ((a & 1) < (b & 1)) ? -1 : 1;
    }
}
 
class GFG{
 
// Function to
static void separateOddEven(int []arr, int N)
{
     
    // Separating them using sort comparator
    // Instantiate the IComparer object
    IComparer cmp = new compare();
    Array.Sort(arr, cmp);
 
    for(int i = 0; i < N; ++i)
    {
        Console.Write(arr[i] + " ");
    }
}
 
// Driver Code
public static void Main(String[] args)
{
    int []arr = { 12, 15, 6, 2, 7, 13, 9, 4 };
    int N = arr.Length;
     
    separateOddEven(arr, N);
}
}
 
// This code is contributed by shikhasingrajput

Javascript

输出

2 4 6 12 7 9 13 15

时间复杂度： O(N*log N)
辅助空间： O(1)