What are the different ways to implement factorial in the C language?

In the C language, factorial can be achieved through recursion and iteration.

1. Recursively:

int factorial(int n) {
    if (n == 0) {
        return 1;
    } else {
        return n * factorial(n-1);
    }
}

1. Iterative approach:

int factorial(int n) {
    int result = 1;
    for (int i = 1; i <= n; i++) {
        result *= i;
    }
    return result;
}

Both methods can calculate the factorial of a given number, but the recursive method is relatively concise, while the iterative method is more memory efficient. The choice of method depends on specific requirements and application scenarios.