public class SelectionSort {
    public static void selectionSort(int[] arr) {
        for (int i = 0; i < arr.length - 1; i++) {
            int minIndex = i;
            for (int j = i + 1; j < arr.length; j++) {
                if (arr[j] < arr[minIndex]) {
                    minIndex = j;
                }
            }
            int temp = arr[i];
            arr[i] = arr[minIndex];
            arr[minIndex] = temp;
        }
    }

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