Zig_Zag_Print

 import java.util.Scanner;

public class Arrays_Exercise {
    public static void main(String[] args) {
Scanner sc = new Scanner(System.in);

        System.out.print("Enter n: ");
        int n = Integer.parseInt(sc.nextLine());

        String[] numbers = new String[n * 2];   // create String array with n * 2 elements to store the numbers we want to print

        int userInputIndex = 0; // create int variable to index each number from the pair of numbers
        for (int i = 0; i < n; i++) {
            System.out.print("Enter two numbers: ");
            String[] userInput = sc.nextLine().split(" "); // create new array to store the pairs of numbers from the user's input
            if (i % 2 == 0) { // create if condition check whether i is even number
                numbers[userInputIndex++] = userInput[0]; // connect userInput array with numbers array
                numbers[userInputIndex++] = userInput[1];
            } else { // or odd number
                numbers[userInputIndex++] = userInput[1];
                numbers[userInputIndex++] = userInput[0];
            }
        }
        String firstOutput = " "; // create String array to store the even i numbers
        String secondOutput = " "; // create String array to store the odd i numbers

        for (int i = 0; i < numbers.length; i++) {  //read the numbers array
            if (i % 2 == 0) {
                firstOutput += numbers[i] + " ";

            } else {
                secondOutput += numbers[i] + " ";

            }
        }
        System.out.println(firstOutput.trim());
        System.out.println(secondOutput.trim());
    }
}