Thread: Two problematic recursive programs

In the pow one I would suggest rename the function to Pow; since pow is a C standard function.
It is unlikely to fix any problem; but, since you state nothing about the problem it worth a try.
Esp. since you have this line in your code of "using namespace std;"

NOTE: Most recursive functions have the stopping condition checks before the recursive function call.
Your second example does NOT follow that pattern.

Edit: Read the 8 common mistakes FAQ you might get a hint on it for the second one.
Edit2: Link http://www.cprogramming.com/tutorial/common.html

Tim S.

Testing issue for "int pow( int base, int exp )" what happens if either base or exp is zero or negative?

Tim S.

Originally Posted by Kelton2

I still don't know what the problem is. For clarifications:

Raise to Power works but produces a garbage result

Define garbage.
It works as expected for me for some numbers, e.g. 10^4:

Code:

#include <iostream>
using namespace std;

int pow(int base, int exp)
{
	if (exp == 0)
	{
		return 1;
	}
	else
	{
		return base * pow(base, exp - 1);
	}
}
int main()
{
	int base;
	int power;
	cout << "This program calculates exponential values." << endl;
	cout << "Enter the base: ";
	cin >> base;
	cout << "Enter the power: ";
	cin >> power;
	cout << "" << endl;
	cout << base << "^" << power << " = ";
	cout << pow(base, power) << "\n";
}

(You can't actually cout cout as you did in your original code, so I removed it.)

When I put in 3 and 2, it gives me 0x44 something something.



EDIT: OMG IT WORKS! Now I just have the other one. Any help there?

Works for me:

Code:

This program calculates exponential values.
Enter the base: 3
Enter the power: 2

3^2 = 9

Show the smallest possible compilable example that exhibits the problem. I can't reproduce the error.

I did not.
As for the other, an educated guess, but this
"else if(number1 || number2 == 0) {"
probably won't do what you think it will.
It actually means
"else if (number1 != 0 || number2 == 0)"
You have to be explicit. It should probably be
"else if (number1 == 0 || number2 == 0)"

I am not taking into account if the actual algorithm is correct or not, however.

Originally Posted by stahta01

NOTE: Most recursive functions have the stopping condition checks before the recursive function call.
Your second example does NOT follow that pattern.

Hint Hint

Tim S.

Originally Posted by Kelton2

What?

Use your mind trace the program with inputs of 0 and 0; what will happen?

Tim S.