/* binary tree for sorting and count words from a stream of text */

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

/* #include "mylib.c" */

#define MAXWORD 100

struct tNode /* tree node */
{
    char *word;
    int count;
    struct tNode *left;
    struct tNode *right;
};

struct tNode *
AddTree(struct tNode *, char *);

void
TreePrint(struct tNode *);

/* here's the declaration I forgot */
#if 0
int
GetWord(char *, int);
#endif

int
main()
{
    struct tNode *root;
    char word[MAXWORD];

    root = NULL;
    while(GetWord(word, MAXWORD) != EOF)
        if(isalpha(word[0]))
            root = AddTree(root, word);
    TreePrint(root);
    return 0;
}



struct tNode *
TreeAlloc(void);

char *
DuplicateString(char *);

struct tNode *
AddTree(struct tNode *p, char *w)
{
    int cond;

    if(p == NULL)
    {
        p = TreeAlloc();
        p->word = DuplicateString(w);
        p->count = 1;
        p->left = p->right = NULL;
    }
    else if((cond = strcmp(w, p->word)) == 0)
    {
        p->count++;
    }
    else if(cond < 0)
    {
        p->left = AddTree(p->left, w);
    }
    else if(cond > 0)
    {
        p->right = AddTree(p->right, w);
    }
    return p;
}

void
TreePrint(struct tNode *p)
{
    if(p != NULL)
    {
        TreePrint(p->left);
        printf("%4d %s\n", p->count, p->word);
        TreePrint(p->right);
    }
}

struct tNode *
TreeAlloc(void)
{
    return(struct tNode *) malloc(sizeof(struct tNode));
}

char *
DuplicateString(char *s)
{
    char *p;

    p = (char *) malloc(strlen(s) + 1); //+1 for the string terminator obviously!
    if(p != NULL)
        strcpy(p, s);
    return p;
}

int GetWord(char *word, int lim)
{
    int c, getch(void);
    void ungetch(int);
    char *w = word;

    while(isspace(c = getch()))
        ;
    if(c != EOF)
        *w++ = c;
    if(!isalpha(c))
    {
        *w++ = '\0';
        return c;
    }
    for(;
        --lim > 0;
        w++)
        if(!isalnum(*w = getch()))
        {
            ungetch(*w);
            break;
        }
    *w = '\0';
    return word[0];
}