public class MergeSort {
//to merge divided array
public static void conquer(int arr[], int si, int mid, int ei) {
int merged[] = new int[ei - si + 1];
int idx1 = si;
int idx2 = mid + 1;
int x = 0;
while (idx1 <= mid && idx2 <= ei) {
if (arr[idx1] <= arr[idx2]) {
merged[x++] = arr[idx1++];
} else {
merged[x++] = arr[idx2++];
}
}
while (idx1 <= mid) {
merged[x++] = arr[idx1++];
}
while (idx2 <= ei) {
merged[x++] = arr[idx2++];
}
//copying sorted array element into original array;
for (int i = 0, j = si; i < merged.length; i++, j++) {
arr[j] = merged[i];
}
}
//to divide the array into smallest array possible
public static void divide(int arr[], int si, int ei) {
if (si >= ei) {
return;
}
int mid = si + (ei - si) / 2;
divide(arr, si, mid);
divide(arr, mid + 1, ei);
conquer(arr, si, mid, ei);
}
public static void main(String args[]) {
int arr[] = { 6, 3, 9, 5, 2, 8 };
int n = arr.length;
divide(arr, 0, n - 1);
for (int i = 0; i < n; i++) {
System.out.print(arr[i] + " ");
}
System.out.println();
}
}
