What's wrong with my Tree ):

[wOo[FIN.K.L]]

Hi there I'm trying to practice trees, and I'm not quite sure how I should implement my main function, although I'm pretty sure My other functions are correct... I could be wrong though :x

#include <stdlib.h>
#include <stdio.h>

typedef struct node *tree;

tree newNode (int newValue);
tree insert(tree node, int newValue); 

int main (int argc, char *argv[]) {

   int newValue;
   scanf ("%d", &newValue);
   newNode (newValue);
   insert(newNode, newValue); 
   return EXIT_SUCCESS;
}

//create a struct called node
typedef struct node {
   int value;
   tree left;
   tree right;
} node;

//New node function,
tree newNode (int newValue) {
   tree node = malloc (sizeof (struct node));
   node->value = newValue;
   node->left = NULL;
   node->right = NULL;
   return node;
}

//inserts a new node with the given number in the correct place in the tree.
// Returns the new root pointer

tree insert(tree node, int newValue) {
  //If the tree is empty, return a new, single node
   if (node == NULL) {
      return(newNode(newValue));
   } else if (newValue < node->value) {   //Otherwise, recur down the tree
      node->left = insert (node->left, newValue);
   } else if (newValue >= node->value) {
      node->right = insert (node->right, newValue);
   }
   return node;
}

   insert(newNode, newValue);

In the above line from my main function, I get an error saying "trees.c:14: warning: passing argument 1 of ‘insert’ from incompatible pointer type" so obviously newNode doesn't belong there, but what Should go in there then?

Thanks guys

[tabstop]

Well, the prototype of insert says it takes a tree. So you should pass the tree you want the value to be inserted in. Since you never bothered to create a tree, you don't have one to insert into. You should probably do that.

[wOo[FIN.K.L]]

but I typedefed tree to be a pointer to a node, and since I created a node using newNode. so Shouldn't I be inserting a Node I want to insert the value in? which in this case is newNode?

thanks for your reply

[tabstop]

newNode is a function, it is not a node itself. newNode returns a node, it is true. You immediately throw it away and stomp on it (i.e., the result is not assigned to anything). And then, you wouldn't have to do insert again, unless you wanted to insert the node a second time.

[wOo[FIN.K.L]]

oh okay, so does that mean newNode creates a new node called "node" when I call it?

so it should be

[code] insert(node, newValue); [\code]

?

I recall doing that and I think I got an error saying node is undefined

[tabstop]

No.

(I suppose you want the full answer: newNode creates a new node, which it returns. It is your responsibility to put that node where you want it, via putting a name on the left side and an = in between.)

[wOo[FIN.K.L]]

ah, that does make a lot more sense... Thanks a lot :]