﻿ Java - An array has every second element over the left, right

# Java: Rearrange a given array of unique elements such that every second element of the array is greater than its left and right elements

## Java Array: Exercise-61 with Solution

Write a Java program to rearrange a given array of unique elements such that every second element of the array is greater than its left and right elements.

Example:
Input :
nums= { 1, 2, 4, 9, 5, 3, 8, 7, 10, 12, 14 }
Output:
Array with every second element is greater than its left and right elements:
[1, 4, 2, 9, 3, 8, 5, 10, 7, 14, 12]

Sample Solution:

Java Code:

``````// Import the necessary Java class.
import java.util.Arrays;

// Define a class named 'solution'.
class solution
{
// A private method to swap two elements in an array.
private static void swap_nums(int[] nums, int i, int j) {
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
}

// A method to rearrange an array such that every second element is greater
// than its left and right elements.
public static void rearrange_Array_nums(int[] nums)
{
for (int i = 1; i < nums.length; i += 2)
{
// Check if the element to the left is greater and swap if needed.
if (nums[i - 1] > nums[i]) {
swap_nums(nums, i - 1, i);
}

// Check if the element to the right is greater and swap if needed.
if (i + 1 < nums.length && nums[i + 1] > nums[i]) {
swap_nums(nums, i + 1, i);
}
}
}

public static void main (String[] args)
{
int[] nums= { 1, 2, 4, 9, 5, 3, 8, 7, 10, 12, 14 };
System.out.println("Original array:\n"+Arrays.toString(nums));

// Rearrange the array so that every second element is greater than its
// left and right elements.
rearrange_Array_nums(nums);

System.out.println("\nArray with every second element is greater than its left and right elements:\n"
+ Arrays.toString(nums));
}
}
```
```

Sample Output:

```Original array:
[1, 2, 4, 9, 5, 3, 8, 7, 10, 12, 14]

Array with every second element is greater than its left and right elements:
[1, 4, 2, 9, 3, 8, 5, 10, 7, 14, 12]
```

Flowchart: Java Code Editor:

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