不在正确位置的元素计数

给定一个由N个元素组成的数组arr [] ，任务是计算该数组中位置不正确的元素的数量。如果元素在排序数组时在数组中的位置发生变化，则称该元素的位置不正确。

例子：

Input: arr[] = {1, 2, 6, 2, 4, 5}
Output: 4
Array in the sorted form will be {1, 2, 2, 4, 5, 6}

Input: arr[] = {1, 2, 3, 4}
Output: 0
All the elements are already sorted.

方法：首先将数组元素复制到另一个数组中，例如B []，然后对给定数组进行排序。开始遍历数组，并且对于每个元素，如果arr [i]！= B [i] ，则该元素不在给定数组中的正确位置。

下面是上述方法的实现：

C++

// C++ implementation of the approach
#include 
using namespace std;
  
// Function to return the count of
// elements which are not in
// the correct position when sorted
int cntElements(int arr[], int n)
{
  
    // To store a copy of the
    // original array
    int copy_arr[n];
  
    // Copy the elements of the given
    // array to the new array
    for (int i = 0; i < n; i++)
        copy_arr[i] = arr[i];
  
    // To store the required count
    int count = 0;
  
    // Sort the original array
    sort(arr, arr + n);
    for (int i = 0; i < n; i++) {
  
        // If current element was not
        // at the right position
        if (arr[i] != copy_arr[i]) {
            count++;
        }
    }
    return count;
}
  
// Driver code
int main()
{
    int arr[] = { 1, 2, 6, 2, 4, 5 };
    int n = sizeof(arr) / sizeof(arr[0]);
  
    cout << cntElements(arr, n);
  
    return 0;
}

Java

// Java implementation of the approach 
import java.util.*;
  
class GFG 
{
      
    // Function to return the count of 
    // elements which are not in 
    // the correct position when sorted 
    static int cntElements(int arr[], int n) 
    { 
      
        // To store a copy of the 
        // original array 
        int copy_arr[] = new int[n]; 
      
        // Copy the elements of the given 
        // array to the new array 
        for (int i = 0; i < n; i++) 
            copy_arr[i] = arr[i]; 
      
        // To store the required count 
        int count = 0; 
      
        // Sort the original array 
        Arrays.sort(arr); 
          
        for (int i = 0; i < n; i++) 
        { 
      
            // If current element was not 
            // at the right position 
            if (arr[i] != copy_arr[i])
            { 
                count++; 
            } 
        } 
        return count; 
    } 
      
    // Driver code 
    public static void main (String[] args)
    { 
        int arr[] = { 1, 2, 6, 2, 4, 5 }; 
        int n = arr.length; 
      
        System.out.println(cntElements(arr, n)); 
    } 
}
  
// This code is contributed by AnkitRai01

Python3

# Python3 implementation of the approach 
  
# Function to return the count of 
# elements which are not in 
# the correct position when sorted 
def cntElements(arr, n) :
  
    # To store a copy of the 
    # original array 
    copy_arr = [0] * n 
  
    # Copy the elements of the given 
    # array to the new array 
    for i in range(n): 
        copy_arr[i] = arr[i] 
  
    # To store the required count 
    count = 0
  
    # Sort the original array 
    arr.sort() 
    for i in range(n): 
  
        # If current element was not 
        # at the right position 
        if (arr[i] != copy_arr[i]) : 
            count += 1
              
    return count
      
# Driver code 
arr = [ 1, 2, 6, 2, 4, 5 ] 
n = len(arr) 
  
print(cntElements(arr, n)) 
  
# This code is contributed by
# divyamohan123

C#

// C# implementation of the approach 
using System;
  
class GFG 
{
      
    // Function to return the count of 
    // elements which are not in 
    // the correct position when sorted 
    static int cntElements(int [] arr, int n) 
    { 
      
        // To store a copy of the 
        // original array 
        int [] copy_arr = new int[n]; 
      
        // Copy the elements of the given 
        // array to the new array 
        for (int i = 0; i < n; i++) 
            copy_arr[i] = arr[i]; 
      
        // To store the required count 
        int count = 0; 
      
        // Sort the original array 
        Array.Sort(arr); 
          
        for (int i = 0; i < n; i++) 
        { 
      
            // If current element was not 
            // at the right position 
            if (arr[i] != copy_arr[i])
            { 
                count++; 
            } 
        } 
        return count; 
    } 
      
    // Driver code 
    public static void Main (String[] args)
    { 
        int [] arr = { 1, 2, 6, 2, 4, 5 }; 
        int n = arr.Length; 
      
        Console.WriteLine(cntElements(arr, n)); 
    } 
}
  
// This code is contributed by Mohit kumar

输出：

4