Write a program for merge sort by using the c++ programming.
#include <iostream>
#include <vector>
void merge(std::vector<int>& arr, int left, int mid, int right) {
int n1 = mid - left + 1;
int n2 = right - mid;
std::vector<int> left_arr(n1);
std::vector<int> right_arr(n2);
for (int i = 0; i < n1; i++) {
left_arr[i] = arr[left + i];
}
for (int j = 0; j < n2; j++) {
right_arr[j] = arr[mid + 1 + j];
}
int i = 0, j = 0, k = left;
while (i < n1 && j < n2) {
if (left_arr[i] <= right_arr[j]) {
arr[k] = left_arr[i];
i++;
} else {
arr[k] = right_arr[j];
j++;
}
k++;
}
while (i < n1) {
arr[k] = left_arr[i];
i++;
k++;
}
while (j < n2) {
arr[k] = right_arr[j];
j++;
k++;
}
}
void mergeSort(std::vector<int>& arr, int left, int right) {
if (left < right) {
int mid = left + (right - left) / 2;
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
merge(arr, left, mid, right);
}
}
int main() {
std::vector<int> arr = {12, 11, 13, 5, 6, 7};
mergeSort(arr, 0, arr.size() - 1);
std::cout << "Sorted array: ";
for (int i = 0; i < arr.size(); i++) {
std::cout << arr[i] << " ";
}
std::cout << std::endl;
return 0;
}