Question

How to create an array from a 2D array that only includes the non-zero elements in Java

Answer 1

import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        int[][] array = {
            { 1, 0, 8, 2 },
            { 0, 7, 3, 0 },
            { 9, 0, 0, 4 }
        };

        List<Integer> nonZeroList = new ArrayList<>();

        // Collect non-zero elements
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[i].length; j++) {
                if (array[i][j] != 0) {
                    nonZeroList.add(array[i][j]);
                }
            }
        }

        // Convert the list back to a one-dimensional array
        int[] resultArray = new int[nonZeroList.size()];
        for (int i = 0; i < nonZeroList.size(); i++) {
            resultArray[i] = nonZeroList.get(i);
        }

        for (int element : resultArray) {
            System.out.print(element + " ");
        }
    }
}



/*
run:

1 8 2 7 3 9 4 

*/

 

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