Wrong Output!

Code:

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#include<cstdlib>
#include<iostream>

using namespace std;

int factorial(int *,int);  //number and result
int main()
{
    int fact,num;
    cout<<"Enter a number!"<<endl;
    cin>>num;
    fact=factorial(&num,1);
    cout<<"fact is : "<<fact<<endl;
    system("PAUSE");
    return 0;
}
int factorial(int *n,int r)
{
    if(*n<=1)
      return r;
    else
    {
        r = r * (*n);
        *n-=1;
        cout<<"r is : "<<r<<endl;
        factorial(n,r);
    } 
}

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This is a factorial program everything works fine, but the output of fact in main is way off and the variable returning to fact in function factorial is giving the right output.

This is the second time this happened, so any ideas?

I'm using Dev-cpp, just for the record!

Thank You!

You are not returning the value when you are recursing inside factorial.

I also see absolutely no point in passing n as a pointer, or passing r around.

--
Mats

If you put warnings to max, don't you get a warning similar to "not all control paths return a value"?

what? if I return the value during recursion the control shifts back to main and i get the wrong output

how do i put warnings to max ?

I have

1)enable exceptional handling
2) generate debugging info

set to yes in the compiler options

Quote:

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Originally Posted by kolliash

what? if I return the value during recursion the control shifts back to main and i get the wrong output

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No you won't, and if you do, the code itself is flawed.
The thing is that if n is NOT <= 1, the function will return NOTHING, ie undefined return.
So the entire result then becomes undefined.

Quote:

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how do i put warnings to max ?

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Typically find options with the command line -wall and maybe pendantic.

Code:

---

#include<cstdlib>
#include<iostream>

using namespace std;

int factorial(int *,int);  //number and result
int main()
{
    int fact,num;
    cout<<"Enter a number!"<<endl;
    cin>>num;
    fact=factorial(&num,1);
    cout<<"fact is : "<<fact<<endl;
    system("PAUSE");
    return EXIT_SUCCESS;
}
int factorial(int *n,int r)
{
    if((*n<=1))
      return r;
    else
    {
       
        r = r * (*n);
        (*n)-=1;
    }
    r=factorial(n,r);
    return r;
}

---

It works!!

Thank You matsp,Elysia

since the return type is int, i forgot to return the value to r for every call.

Good. Now simplify your code to work with:

Code:

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int factorial(int n);

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