package Sorts;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;
public class MergeSortRecursive {
List arr;
public MergeSortRecursive(List arr) {
this.arr = arr;
}
public void mergeSort() {
List arrSorted = merge(arr);
System.out.println(arrSorted);
}
private static List merge(List arr) {
// base condition
if (arr.size() <= 1) {
return arr;
}
int arrLength = arr.size();
int half = arrLength / 2;
List arrA = arr.subList(0, half);
List arrB = arr.subList(half, arr.size());
// recursion
arrA = merge(arrA);
arrB = merge(arrB);
return sort(arrA, arrB);
}
private static List sort(List unsortedA, List unsortedB) {
if (unsortedA.size() <= 0 && unsortedB.size() <= 0) {
return new ArrayList<>();
}
if (unsortedA.size() <= 0) {
return unsortedB;
}
if (unsortedB.size() <= 0) {
return unsortedA;
}
if (unsortedA.get(0) <= unsortedB.get(0)) {
List newAl = new ArrayList() {
{
add(unsortedA.get(0));
}
};
newAl.addAll(sort(unsortedA.subList(1, unsortedA.size()), unsortedB));
return newAl;
} else {
List newAl = new ArrayList() {
{
add(unsortedB.get(0));
}
};newAl.addAll(sort(unsortedA, unsortedB.subList(1, unsortedB.size())));
return newAl;
}
}
}
class App {
public static void main(String[] args) {
MergeSortRecursive sort = new MergeSortRecursive(new ArrayList<>(Arrays.asList(4, 3, 1, 8, 5, 10, 0, 1, 4, 11, 8, 9)));
sort.mergeSort();
}
}