Binary Tree in C Insertion Error
- by Paul
I'm quite new to C and I'm trying to implement a Binary Tree in C which will store a number and a string and then print them off e.g.
1 : Bread
2 : WashingUpLiquid
etc.
The code I have so far is:
#include <stdio.h>
#include <stdlib.h>
#define LENGTH 300
struct node {
 int data;
 char * definition;
 struct node *left;
 struct node *right;
};
struct node *node_insert(struct node *p, int value, char * word);
void print_preorder(struct node *p);
int main(void) {
 int i = 0;
 int d = 0;
 char def[LENGTH];
 struct node *root = NULL; 
 for(i = 0; i < 2; i++)
 {
 printf("Please enter a number: \n");
 scanf("%d", &d);
 printf("Please enter a definition for this word:\n");
 scanf("%s", def);
 root = node_insert(root, d, def);
 printf("%s\n", def);
 }
 printf("preorder : ");
 print_preorder(root);
 printf("\n");
 return 0;
}
struct node *node_insert(struct node *p, int value, char * word) {
 struct node *tmp_one = NULL;
 struct node *tmp_two = NULL;
 if(p == NULL) {
  p = (struct node *)malloc(sizeof(struct node));
  p->data = value;
  p->definition = word;
  p->left = p->right = NULL;
 } else {
  tmp_one = p;
  while(tmp_one != NULL) {
   tmp_two = tmp_one;
   if(tmp_one->data > value)
    tmp_one = tmp_one->left;
   else
    tmp_one = tmp_one->right;
  }
  if(tmp_two->data > value) {
   tmp_two->left = (struct node *)malloc(sizeof(struct node));
   tmp_two = tmp_two->left;
   tmp_two->data = value;
   tmp_two->definition = word;
   tmp_two->left = tmp_two->right = NULL;
  } else {
   tmp_two->right = (struct node *)malloc(sizeof(struct node)); 
   tmp_two = tmp_two->right;
   tmp_two->data = value;
   tmp_two->definition = word;
   tmp_two->left = tmp_two->right = NULL;
  }
 }
 return(p);
}
void print_preorder(struct node *p) {
 if(p != NULL) {
  printf("%d : %s\n", p->data, p->definition);
  print_preorder(p->left);
  print_preorder(p->right);
 }
}
At the moment it seems to work for the ints but the description part only prints out for the last one entered. I assume it has something to do with pointers on the char array but I had no luck getting it to work. Any ideas or advice?
Thanks