Ackermann, heavily recursive function

ackerman.cpp

// ackerman.cpp
// juanfc 2025-11-01
// ackermann(4, 0) -> 13
// ackermann(4, 1) -> 65533
// ackermann(4, 2) -> … 19,729 digits …
//
// https://gist.github.com/juanfal/79ca4e73649a5a0b3fe3fd82923f3e4e

#include <iostream>
using namespace std;

int main()
{
    int ackermann(int, int);

    int m, n;
    do {
        cout << "Introducir m y n: ";
        cin >> m >> n;
        cout << "ackermann(" << m << "," << n << "): " << ackermann(m, n) << endl;
    } while (m != 0 or n != 0);

    return 0;
}

int ackermann(int m, int n)
{
    if (m == 0)
        return n+1;
    else if (n == 0)
        return ackermann(m-1, 1);
    else
        return ackermann(m-1, ackermann(m, n-1));
}

ackermann.cpp

// ackermann.cpp
// juanfc 2025-11-01
// ackermann(4, 0) -> 13
// ackermann(4, 1) -> 65533
// ackermann(4, 2) -> … 19,729 digits …
//
// https://gist.github.com/juanfal/79ca4e73649a5a0b3fe3fd82923f3e4e
#include <iostream>
using namespace std;

int main()
{
    int ackermann(int, int);

    int m, n;
    do {
        cout << "Introducir m y n: ";
        cin >> m >> n;
        cout << "ackermann(" << m << "," << n << "): " << ackermann(m, n) << endl;
    } while (m != 0 or n != 0);

    return 0;
}

int ackermann(int m, int n)
{
    if (m == 0)
        return n+1;
    else if (n == 0)
        return ackermann(m-1, 1);
    else
        return ackermann(m-1, ackermann(m, n-1));
}