class MergeSort { void merge(int arr[], int l, int m, int r) { int n1 = m - l + 1; int n2 = r - m; int L[] = new int[n1]; int R[] = new int[n2]; for (int i = 0; i < n1; ++i) L[i] = arr[l + i]; for (int j = 0; j < n2; ++j) R[j] = arr[m + 1 + j]; int i = 0, j = 0; int k = l; while (i < n1 && j < n2) { if (L[i] <= R[j]) { arr[k] = L[i]; i++; } else { arr[k] = R[j]; j++; } k++; } while (i < n1) { arr[k] = L[i]; i++; k++; } while (j < n2) { arr[k] = R[j]; j++; k++; } } void sort(int arr[], int l, int r) { if (l < r) { int m = (l + r) / 2; sort(arr, l, m); sort(arr, m + 1, r); merge(arr, l, m, r); } } static void printArray(int arr[]) { int n = arr.length; for (int i = 0; i < n; ++i) System.out.print(arr[i] + " "); System.out.println(); } public static void main(String args[]) { int arr[] = { 12, 11, 13, 5, 6, 7 }; System.out.println("Given Array"); printArray(arr); MergeSort ob = new MergeSort(); ob.sort(arr, 0, arr.length - 1); System.out.println("\nSorted array"); printArray(arr); } }