生成具有前一个元素和下一个元素的按位与的数组

给定一个包含N个元素的整数数组arr[] ，任务是生成另一个数组，该数组具有前一个元素和下一个元素的（按位）与，但有以下例外。

1. 第一个元素是第一个和第二个元素的按位与。
2. 最后一个元素是最后一个和倒数第二个元素的按位与。

例子：

Input: arr[] = {1, 2, 3, 4, 5, 6} 
Output: 0 1 0 1 4 4 
The new array will be {1 & 2, 1 & 3, 2 & 4, 3 & 5, 4 & 6, 5 & 6}

Input: arr[] = {9, 8, 7} 
Output: 8 1 0 

方法：新数组的第一个和第二个元素可以分别计算为arr[0] & arr[1]和arr[N – 1] & arr[N – 2] 。其余元素可以计算为arr[i – 1] & arr[i + 1] 。

下面是上述方法的实现：

C++

// C++ implementation of the approach
#include 
using namespace std;
 
// Function to generate the array that
// satisfies the given condition
void generateArr(int arr[], int n)
{
 
    // If there is only a single element
    // in the array
    if (n == 1) {
        cout << arr[0];
        return;
    }
 
    // To store the generated array
    int barr[n];
 
    // First element
    barr[0] = arr[0] & arr[1];
 
    // Last element
    barr[n - 1] = arr[n - 1] & arr[n - 2];
 
    // Rest of the elements
    for (int i = 1; i < n - 1; i++)
        barr[i] = arr[i - 1] & arr[i + 1];
 
    // Print the generated array
    for (int i = 0; i < n; i++)
        cout << barr[i] << " ";
}
 
// Driver code
int main()
{
    int arr[] = { 1, 2, 3, 4, 5, 6 };
    int n = sizeof(arr) / sizeof(arr[0]);
 
    generateArr(arr, n);
 
    return 0;
}

Java

// Java implementation of the approach
import java .io.*;
 
class GFG
{
static void generateArr(int[] arr, int n)
{
    // Nothing to do when array size is 1
    if (n <= 1)
        return;
 
    // store current value of arr[0]
    // and update it
    int prev = arr[0];
    arr[0] = arr[0] & arr[1];
 
    // Update rest of the array elements
    for (int i = 1; i < n - 1; i++)
    {
        // Store current value of
        // next interation
        int curr = arr[i];
 
        // Update current value using
        // previous value
        arr[i] = prev & arr[i + 1];
 
        // Update previous value
        prev = curr;
    }
 
    // Update last array element separately
    arr[n - 1] = prev & arr[n - 1];
}
 
// Driver Code
public static void main(String[] args)
{
    int[] arr = { 1, 2, 3, 4, 5, 6 };
    int n = arr.length;
 
    generateArr(arr, n);
 
    // Print the modified array
    for (int i = 0; i < n; i++)
        System.out.print(arr[i] + " ");
}
}
 
// This code is contributed by Nikhil

Python3

# Python3 implementation of the approach
 
# Function to generate the array that
# satisfies the given condition
def generateArr(arr, n):
     
    # If there is only a single element
    # in the array
    if (n == 1):
        print(arr[0]);
        return;
 
    # To store the generated array
    barr = [0] * n;
 
    # First element
    barr[0] = arr[0] & arr[1];
 
    # Last element
    barr[n - 1] = arr[n - 1] & arr[n - 2];
 
    # Rest of the elements
    for i in range(1, n - 1):
        barr[i] = arr[i - 1] & arr[i + 1];
 
    # Print the generated array
    for i in range(n):
        print(barr[i], end = " ");
 
# Driver Code
if __name__ == '__main__':
    arr = [1, 2, 3, 4, 5, 6];
    n = len(arr);
 
    generateArr(arr, n);
 
# This code is contributed by 29AjayKumar

C#

// C# implementation of the approach
using System;
class GFG
{
static void generateArr(int[] arr, int n)
{
    // Nothing to do when array size is 1
    if (n <= 1)
        return;
 
    // store current value of arr[0]
    // and update it
    int prev = arr[0];
    arr[0] = arr[0] & arr[1];
 
    // Update rest of the array elements
    for (int i = 1; i < n - 1; i++)
    {
        // Store current value of
        // next interation
        int curr = arr[i];
 
        // Update current value using
        // previous value
        arr[i] = prev & arr[i + 1];
 
        // Update previous value
        prev = curr;
    }
 
    // Update last array element separately
    arr[n - 1] = prev & arr[n - 1];
}
 
// Driver Code
static public void Main ()
{
    int[] arr = { 1, 2, 3, 4, 5, 6 };
    int n = arr.Length;
 
    generateArr(arr, n);
 
    // Print the modified array
    for (int i = 0; i < n; i++)
        Console.Write(arr[i] + " ");
}
}
 
// This code is contributed by ajit.

Javascript

 
    // Javascript implementation of the approach
     
    // Function to generate the array that
    // satisfies the given condition
    function generateArr(arr, n)
    {
       
        // If there is only a single element
        // in the array
        if (n == 1) {
            document.write(arr[0]);
            return;
        }
       
        // To store the generated array
        let barr = new Array(n);
       
        // First element
        barr[0] = arr[0] & arr[1];
       
        // Last element
        barr[n - 1] = arr[n - 1] & arr[n - 2];
       
        // Rest of the elements
        for (let i = 1; i < n - 1; i++)
            barr[i] = arr[i - 1] & arr[i + 1];
       
        // Print the generated array
        for (let i = 0; i < n; i++)
            document.write(barr[i] + " ");
    }
     
    let arr = [ 1, 2, 3, 4, 5, 6 ];
    let n = arr.length;
   
    generateArr(arr, n);
 

输出：

0 1 0 1 4 4

时间复杂度： O(N)