Thread: Binary Tree doesn't print it's elements

Hi guys,

I want to read a file full of names and put every name in a sorted binary tree.

I managed to read every name and "store" it in the tree, but when I want to print all
names, it doesn't print any of them.

Here's the code:

Code:

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#define MAXLEN 32

static FILE *file;

struct tnode {
    char *name;
    int count;
    struct tnode *left;
    struct tnode *right;
};

struct tnode *addtree(struct tnode *, char *);
void treeprint(struct tnode *);
int getname(char *, int);

int main()
{
    struct tnode *root;
    char name[MAXLEN];

    file = fopen("names.txt", "r");
    root = NULL;
    while(getname(name, MAXLEN) != EOF)
        if(isalpha(name[0]))
            addtree(root, name);

    treeprint(root);
    return 0;
}

struct tnode *addtree(struct tnode *p, char *w)
{
    int cond;

    if(p == NULL) {
        p = (struct tnode *) malloc(sizeof(struct tnode));
        p -> name = strdup(w);
        //printf("%s", p -> name);
        p -> count = 1;
        p -> left = p -> right = NULL;
    } else if((cond = strcmp(w, p -> name)))
        p -> count++;
    else if(cond < 0)
        p -> left = addtree(p -> left, w);
    else
        p -> right = addtree(p -> right, w);
}

void treeprint(struct tnode *p)
{
    if(p != NULL) {
        treeprint(p -> left);
        printf("%s\n", p -> name);
        treeprint(p -> right);
    }
}

int getname(char *name, int lim)
{
    int c;
    char *w = name;

    while(--lim > 0 && (c = getc(file)) != EOF && isalpha(c))
        *w++ = c;

    if(c == EOF) {
        ungetc(c, file);
        return EOF;
    }

    *w = '\0';
    return name[0];
}

The file is in the attachment.

I hope someone can point out my mistake(s).

greetz