Array Loop moving space complexity is O (1)

The principle is very simple: Flip the previous array elements, flip the array elements that follow, and finally flip the entire array element


#include<iostream>
#defineN -
using namespacestd;

void Reverse (int L,int R,int* Array)
{
 double mid= (l+r)/2.0;
 For (int i=l;i<mid;++i)
 { 
Array[i]=array[r+l-i]+array[i];
Array[r+l-i]=array[i]-array[r+l-i];
Array[i]=array[i]-array[r+l-i];
 }
}
int main ()
{
 int array[n],a,b;
cout<<"Array Length:";
Cin>>a;
cout<<"Please enter an array element:";
 For (int i=0;i<a;++i)
Cin>>array[i];
cout<<"where the loop starts:";
Cin>>b;
Reverse (0,a-b-1,array);
Reverse (a-b,a-1,array);
Reverse (0,a-1,array);
 For (int i=0;i<a;i++)
cout  <<* (array+i)<<"";
 return   0;
}

Array Loop moving space complexity is O (1)