public class Main {
 
    public static void main(String args[]) {
        int[] a = new int[]{6, 0, 8, 2, 3, 0, 4, 0, 1};
        moveZerosToEnd(a);
        for (int c : a) {
            System.out.print(c + " ");
        }
    }
 
    private static void moveZerosToEnd(int[] a) {
        int z = -1;
        for (int i = 0; i < a.length; i++) {
            int c = a[i];
            if (c == 0 && z == -1) {
                z = i;
                continue;
            }
            if (c != 0 && z != -1) {
                swap(a, i, z);
                z++;
            }
        }
    }
 
    private static void swap(int[] a, int i, int j) {
        int x = a[i];
        a[i] = a[j];
        a[j] = x;
    }
}
 

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