Merge sort in c++
#include <iostream>
using namespace std;
void merge(int arr[], int l, int m, int r)
{
int n1 = m - l + 1;
int n2 = r - m;
int L[n1], R[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;
int 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 mergeSort(int arr[],int l,int r){
if(l>=r){
return;
}
int m = (l+r-1)/2;
mergeSort(arr,l,m);
mergeSort(arr,m+1,r);
merge(arr,l,m,r);
}
void printArray(int A[], int size)
{
for (int i = 0; i < size; i++)
cout << A[i] << " ";
}
int main()
{
int arr[] = { 12, 11, 13, 5, 6, 7 };
int arr_size = sizeof(arr) / sizeof(arr[0]);
cout << "Given array is \n";
printArray(arr, arr_size);
mergeSort(arr, 0, arr_size - 1);
cout << "\nSorted array is \n";
printArray(arr, arr_size);
return 0;
}