数组中偶数和奇数索引元素的绝对差

给定一个整数数组arr ，任务是分别在偶数和奇数索引位置找到元素的运行绝对差。
注意：数组考虑基于 0 的索引。即数组中第一个元素的索引为零。
例子：

Input: arr[] = {1, 2, 3, 4, 5, 6} 
Output: Even Index absolute difference : 3 
Odd Index absolute difference : 4 
Explanation : 
Here, even indexed elements are 1, 3 and 5 
So the even absolute difference will be (|1 – 3| = 2) => (|2 – 5| = 3) 
Similarly odd indexed elements are 2, 4 and 6 
And the odd absolute difference will be (|2 – 4| = 2) => (|2 – 6| = 4)
Input: arr[] = {10, 20, 30, 40, 50, 60, 70} 
Output: Even Index absolute difference : 40 
Odd Index absolute difference : 40 
 

方法：遍历数组，保持偶数和奇数两个变量分别存储偶数和奇数索引元素的绝对差。遍历时检查当前索引是否为偶数，即(i%2) == 0 。最后打印结果。
下面是上述方法的实现：

C++

// CPP program to find absolute difference of elements
// at even and odd index positions separately
#include 
using namespace std;
 
// Function to calculate absolute difference
void EvenOddAbsoluteDifference(int arr[], int n)
{
    int even = 0;
    int odd = 0;
 
    for (int i = 0; i < n; i++) {
 
        // Loop to find even, odd absolute difference
        if (i % 2 == 0)
            even = abs(even - arr[i]);
        else
            odd = abs(odd - arr[i]);
    }
 
    cout << "Even Index absolute difference : " << even;
    cout << endl;
    cout << "Odd Index absolute difference : " << odd;
}
 
// Driver Code
int main()
{
    int arr[] = { 1, 2, 3, 4, 5, 6 };
    int n = sizeof(arr) / sizeof(arr[0]);
 
    EvenOddAbsoluteDifference(arr, n);
 
    return 0;
}

Java

// Java program to find absolute difference of elements
// at even and odd index positions separately
 
public class GFG{
     
    // Function to calculate absolute difference
    static void EvenOddAbsoluteDifference(int arr[], int n)
    {
        int even = 0;
        int odd = 0;
     
        for (int i = 0; i < n; i++) {
     
            // Loop to find even, odd absolute difference
            if (i % 2 == 0)
                even = Math.abs(even - arr[i]);
            else
                odd = Math.abs(odd - arr[i]);
        }
     
        System.out.println("Even Index absolute difference : " + even);
        System.out.println("Odd Index absolute difference : " + odd);
    }
 
 
     // Driver Code
     public static void main(String []args){
          
              int arr[] = { 1, 2, 3, 4, 5, 6 };
              int n = arr.length;
 
             EvenOddAbsoluteDifference(arr, n);
     }
     // This code is contributed by ANKITRAI1
}

Python3

# Python 3 program to find absolute difference of
# elements at even and odd index positions separately
 
# Function to calculate absolute difference
def EvenOddAbsoluteDifference(arr, n):
    even = 0
    odd = 0
 
    for i in range(0, n, 1):
         
        # Loop to find even, odd absolute
        # difference
        if (i % 2 == 0):
            even = abs(even - arr[i]);
        else:
            odd = abs(odd - arr[i]);
 
    print("Even Index absolute difference :", even)
    print("Odd Index absolute difference :", odd)
 
# Driver Code
if __name__ == '__main__':
    arr = [1, 2, 3, 4, 5, 6]
    n = len(arr)
 
    EvenOddAbsoluteDifference(arr, n)
     
# This code is contributed by
# Sahil_shelangia

C#

// C# program to find absolute difference
// of elements at even and odd index
// positions separately
using System;
 
class GFG
{
// Function to calculate absolute difference
static void EvenOddAbsoluteDifference(int []arr,
                                      int n)
{
    int even = 0;
    int odd = 0;
 
    for (int i = 0; i < n; i++)
    {
 
        // Loop to find even, odd
        // absolute difference
        if (i % 2 == 0)
            even = Math.Abs(even - arr[i]);
        else
            odd = Math.Abs(odd - arr[i]);
    }
 
    Console.WriteLine("Even Index absolute " +
                      "difference : " + even);
    Console.WriteLine("Odd Index absolute " +
                      "difference : " + odd);
}
 
// Driver Code
static public void Main ()
{
    int []arr = { 1, 2, 3, 4, 5, 6 };
    int n = arr.Length;
    EvenOddAbsoluteDifference(arr, n);
}
}
 
// This code is contributed by Sachin

Javascript

 
    // Javascript program to find absolute difference
    // of elements at even and odd index
    // positions separately
     
    // Function to calculate absolute difference
    function EvenOddAbsoluteDifference(arr, n)
    {
        let even = 0;
        let odd = 0;
 
        for (let i = 0; i < n; i++)
        {
 
            // Loop to find even, odd
            // absolute difference
            if (i % 2 == 0)
                even = Math.abs(even - arr[i]);
            else
                odd = Math.abs(odd - arr[i]);
        }
 
        document.write("Even Index absolute " +
                          "difference : " + even + "</br>");
        document.write("Odd Index absolute " +
                          "difference : " + odd + "</br>");
    }
     
    let arr = [ 1, 2, 3, 4, 5, 6 ];
    let n = arr.length;
    EvenOddAbsoluteDifference(arr, n);
     

输出：

Even Index absolute difference : 3
Odd Index absolute difference : 4

时间复杂度： O(n)