wave_sort.java

import java.util.Arrays;

public class wave_sort {
 public static void wave_sort(int[] arr) {
 // Sorting the array in ascending order
 Arrays.sort(arr);

 // Swapping the elements in pairs
 for (int i = 0; i < arr.length - 1; i += 2) {
 int temp = arr[i];
 arr[i] = arr[i + 1];
 arr[i + 1] = temp;
 }
 }

 public static void main(String[] args) {
 int[] arr = {1, 2, 3, 4, 5, 6, 7, 8, 9};

 waveSort(arr);

 System.out.println(Arrays.toString(arr)); // [2, 1, 4, 3, 6, 5, 8, 7, 9]
 }
}