Question

I’m trying to write a recursive power function without using math.h / pow(), but I keep getting garbage values of -1.#IND. I think i’m missing something when I call for a new instance of the power function, but I don’t quite understand how to get around it. My full code is fairly short:

#include <iostream>
using namespace std;

double power(double b, int e){
    double x;

    if(e == 0){
        x = b;
    }
    else if(b == 0){
        x = 1;
        e = 0;
    }
    else if(e < 0){
        x = (1 / b) * power(b, ++e);
    }
    else{
        x = b * power(b, --e);
    }

    return x;
}

int main(){
    double num;
    int exp;

    cout << "Please Enter Your Number: ";
    cin >> num;

    cout << "Please Enter The Explonent: ";
    cin >> exp;

    cout << power(num, exp);
    cin >> num;
}

Answer 1

The only place you return a value from power is where e==0.

The other cases compute values, but never return them.