Pointer vs Reference Swap

#include <iostream>

// Define swapPtr(int* a, int* b)
void swapPtr(int* a, int* b)
{
    if (!a || !b) return; 
    int temp = *a;
    *a = *b;
    *b = temp; 
}

// Define swapRef(int& a, int& b)
void swapRef(int& a, int& b)
{
    int temp = a; 
    a = b; 
    b = temp; 
}

int main() {
    int x, y;
    std::cin >> x >> y;

    int a = x, b = y;
    swapPtr(&a, &b);
    std::cout << "After swapPtr: a=" << a << " b=" << b << "\n";

    int c = x, d = y;
    swapRef(c, d);
    std::cout << "After swapRef: a=" << c << " b=" << d;

    return 0;
}

Solving Approach