Convert_array_into_Zig-Zag_fashion.java

import java.util.*;
import java.io.*;

public class Main {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int tc = Integer.parseInt(br.readLine().trim());
        while (tc-- > 0) {
            String[] inputLine;
            int n = Integer.parseInt(br.readLine().trim());
            int[] arr = new int[n];
            inputLine = br.readLine().trim().split(" ");
            for (int i = 0; i < n; i++) {
                arr[i] = Integer.parseInt(inputLine[i]);
            }

            new Solution().zigZag(arr, n);
            for (int i = 0; i < n; i++) {
                System.out.print(arr[i] + " ");
            }
            System.out.println();
        }
    }
}

class Solution {
    void zigZag(int arr[], int n) {
        boolean flag = true;
        int temp = 0;
        
        for(int i = 0; i<n-1; i++){
            if( flag ){
                if( arr[i] > arr[i+1] ){
                    temp = arr[i];
                    arr[i] = arr[i+1];
                    arr[i+1] = temp;
                }
            }else{
                if( arr[i] < arr[i+1] ){
                    temp = arr[i];
                    arr[i] = arr[i+1];
                    arr[i+1] = temp;
                }
            }
            flag = !flag;
        }
    }

}