I need a implementation of IN PLACE MERGE SORT in C language

I need a implementation of IN PLACE MERGE SORT, in C++ language, that will work on a vector of integers.

Answer:-

#include <iostream>
using namespace std;

//The merge function
void merge(int a[], int startIndex, int endIndex)
{

int size = (endIndex - startIndex) + 1;
int *b = new int [size]();

int i = startIndex;
int mid = (startIndex + endIndex)/2;
int k = 0;
int j = mid + 1;

while (k < size)
{
if((i<=mid) && (a[i] < a[j]))
{
b[k++] = a[i++];
}
else
{
b[k++] = a[j++];
}

}

for(k=0; k < size; k++)
{
a[startIndex+k] = b[k];
}

delete []b;

}

//The recursive merge sort function
void merge_sort(int iArray[], int startIndex, int endIndex)
{
int midIndex;

//Check for base case
if (startIndex >= endIndex)
{
return;
}

//First, divide in half
midIndex = (startIndex + endIndex)/2;

//First recursive call
merge_sort(iArray, startIndex, midIndex);

//Second recursive call
merge_sort(iArray, midIndex+1, endIndex);

//The merge function
merge(iArray, startIndex, endIndex);

}

//The main function
int main(int argc, char *argv[])
{
int iArray[10] = {2,5,6,4,7,2,8,3,9,10};

merge_sort(iArray, 0, 9);

//Print the sorted array
for(int i=0; i < 10; i++)
{
cout << iArray[i] << endl;
}

return 0;
}