User input to 2 separate arrays in Java

Question

What I want to do is to add 2 elements per line into 2 separate arrays. The first element goes to the X array and the second element goes to the Y array.

public static void main(String[] args) throws IOException {
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(reader.readLine());

    double[] X = new double[n];
    double[] Y = new double[n];

    String[] elem = reader.readLine().split(" ");
    for (int i = 0; i < n; i++) {
        X[i] = Integer.parseInt(elem[n]);
        Y[i] = Integer.parseInt(elem[n]);
    }
    System.out.println(X, Y);
}

input:

3 4
1 1
2 3

where the first column is array X and the second column is array Y. I played with code several times but it still gives me: "Index 2 out of bounds for length 2".

Answer 1

You have to read your lines inside the for loop. X[i] corresponds to elem[0]; Y[i] corresponds to elem[1]. For example:

import java.io.*;
import java.util.*;
public class App {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(reader.readLine());

        double[] X = new double[n];
        double[] Y = new double[n];

        for (int i = 0; i < n; i++) {
            String[] elem = reader.readLine().split(" ");
            X[i] = Integer.parseInt(elem[0]);
            Y[i] = Integer.parseInt(elem[1]);
        }
        System.out.println(Arrays.toString(X));
        System.out.println(Arrays.toString(Y));
    }
}