public class InsertionSort {
    public static void insertionSort(int[] arr) {
        for (int i = 1; i < arr.length; i++) {
            int current = arr[i];
            int j = i - 1;
            while (j >= 0 && arr[j] > current) {
                arr[j + 1] = arr[j];
                j--;
            }
            arr[j + 1] = current;
        }
    }

    public static void main(String[] args) {
        int[] data = {40, 70, 20, 90, 30, 80, 20};
        insertionSort(data);
        for (int n : data) {
            System.out.print(n + " ");
        }
        System.out.println();
    }
}