reverse function with arrays c++

[joycelyn]

I know that I am not supposed to be posting homework questions, however, I am so stumped. I had asked all my friends, searched online, and checked other forums here with no help at all, so please help me.

The question is:

Write an reverse function:
This function should take 2 parameters: a 1D int array and the number of elements.
It should reverse the order of the elements. It should not return anything.
Hint: You can use the swap function to swap two elements, for example swap(a[i], a[j]) would swap a[i] and a[j].

#include <iostream>
#include <algorithm>
using namespace std;

void reverse(int a[], int size) {
   for( int x = 0; x < size; x++){
       for (int y = size; y >= 0; y--){
       swap ( a[x], a[y]);}
   }
}

int main (){
 int a[4] = {7, 2, 8, 3};
 int b[5] = {3, 4, 5, 6, 7};

reverse(a, 4);
reverse(b, 5);
   cout << "Array a reversed: ";
   for (int i = 0; i < 4; ++i)
      cout << a[i] << " ";
   cout << endl;
   cout << "Array b reversed: ";
   for (int i = 0; i < 5; ++i)
      cout << b[i] << " ";
   cout << endl;
return 0;
}

The code doesn't work and I am having trouble understanding why. I had tried to pick apart the code and understand what I am making each loop do but the result is making me confused because it is not what I am thinking it is.

Any help is appreciated. Thank you for your time.

[salem c]

Add this line of code inside your inner loop.
cout << "Swapping " << a[x] << " with " << a[y] << endl;

And this is the very start of the output.

Swapping 7 with 3
Swapping 3 with 3

OK, 7 and 3 looks good, but 3 with 3!?
Surely some mistake.

Perhaps also output the x and y values in the diagnostic for extra clues.