public class InsertionSort {
public static void main(String[] args) {
int[] array = new int[]{5, 3, 9, 1, 6, 4, 10, 2, 8, 7, 15, 3, 2};
System.out.println("Before: " + Arrays.toString(array));
sort(array);
System.out.println("After: " + Arrays.toString(array));
}
public static void sort(int[] arr) {
// This sort algorithm is similar with Bubble sort, the difference is that Bubble always find the
// minimum of the sub array and swap it to the head of the subarray.
// The core idea of insertion sort is that make the small scale sub array ordered, then every time enlarge
// the size of sub arrays by 1 slot meanwhile place the newly added element in proper position so that the
// new sub array is still ordered.
for (int i = 0; i < arr.length - 1; i++) {
for (int j = i + 1; j > 0; j--) {
if (arr[j - 1] <= arr[j]) {
break;
}
swap(arr, j - 1, j);
}
}
}
private static void swap(int[] arr, int i, int j) {
int tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
}