#includeThe above implementation of the merge sort algorithm does not make use of any external package libraries. Another example of solution partition is the divide-and-conquer approach. This algorithm solves a problem by breaking it down into subproblems, solving these subproblems, and then combining the solutions to form a final solution. This approach is used in several algorithms such as binary search, quicksort, and the Karatsuba multiplication algorithm. The C++ standard library offers several algorithms that implement the divide-and-conquer approach such as `std::merge` and `std::sort`. These algorithms make use of the `std::function` library to implement arbitrary function objects that can be used to partition and solve problems.#include using namespace std; void merge(int arr[], int l, int m, int r) { int i, j, k; int n1 = m - l + 1; int n2 = r - m; int L[n1], R[n2]; for (i = 0; i < n1; i++) L[i] = arr[l + i]; for (j = 0; j < n2; j++) R[j] = arr[m + 1+ j]; i = 0; j = 0; 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 mergeSort(int arr[], int l, int r) { if (l < r) { int m = l+(r-l)/2; mergeSort(arr, l, m); mergeSort(arr, m+1, r); merge(arr, l, m, r); } } int main() { int arr[] = {12, 11, 13, 5, 6, 7}; int arr_size = sizeof(arr)/sizeof(arr[0]); cout << "Given array is \n"; for (int i = 0; i < arr_size; i++) cout << arr[i] << " "; mergeSort(arr, 0, arr_size - 1); cout << "\nSorted array is \n"; for (int i = 0; i < arr_size; i++) cout << arr[i] << " "; return 0; }