Binary Search Tree error

Question

I want to find minimum value in a Binary Search Tree. I have written below code. But when i call the function from main and I pribt the return value, it is printing as 0 always.

cal you please help.

int findMinimumValue(struct tnode* node)
{
int min=node->data;
if(node->lchild==NULL)
{
   return min;
}
else
    findMinimumValue(node->lchild);
}

What language is this? (Please tag the question appropriately.) Have you attempted to debug this? — Oliver Charlesworth
– Oliver Charlesworth, Commented Aug 21, 2011 at 11:01
If you turned up your compiler's warning level, you would find the problem immediately. — Oliver Charlesworth
– Oliver Charlesworth, Commented Aug 21, 2011 at 11:04
I did not get any error while I was running and compiling the code. — aj983
– aj983, Commented Aug 21, 2011 at 11:06
Tree created is fine. i am able to traverse the tree properly. But I dont know why the value is comin out to be 0. Below is the way i have made a call to the function. cout<<findMinimumValue(root) — aj983
– aj983, Commented Aug 21, 2011 at 11:08
Yes, exactly. You should set your compiler to use a higher warning level. (In GCC, you can do -Wall -Wextra; in VS you can use /W3 or /W4.) — Oliver Charlesworth
– Oliver Charlesworth, Commented Aug 21, 2011 at 11:09

shelleybutterfly · Accepted Answer · 2011-08-21 11:20:15Z

6

Looks like you're not actually returning the value of your recursion call:

int findMinimumValue(struct tnode* node)
{
    int min=node->data;

    if(node->lchild==NULL)
    {
        return min;
    }
    else
    {
        // you need the return here or you're never returning 
        // anything in this branch
        return findMinimumValue(node->lchild);
    }
}

for that matter not really much need for the variable as it is, what about:

int findMinimumValue(struct tnode* node)
{
    if (node->lchild == NULL)
        return node->data;
    else
        return findMinimumValue(node->lchild);
}

oh, and just as a mention: I would consider using the non-recursive version of this instead; it's also pretty simple:

int findMinimumValue(struct tnode* node)
{
    while (node->lchild != NULL)
        node = node->lchild;

    return node->data;
}

edited Aug 21, 2011 at 11:20

answered Aug 21, 2011 at 11:07

shelleybutterfly

3,23918 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

shelleybutterfly Over a year ago

bleah, getting too late to write answers had to edit twice because somehow I went from thinking "no return in this branch" to typing "min =". in two places.

aj983 Over a year ago

Thanks. Now it worked. It was a stupid mistake from my side. I have many problems in recursion. can you please suggest some tutorial link ets to improve the concept.

shelleybutterfly Over a year ago

:) I've been there, no worries. recursion can be hard. as for a tutorial, a quick google turned this one up, it seemed pretty cool: erwnerve.tripod.com/prog/recursion

Collectives™ on Stack Overflow

Binary Search Tree error

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related