dataStructure/tnode.c at master · taohi/dataStructure · GitHub

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

#define MAXWORD 100

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

struct tnode *addtree(struct tnode *,char *);
void treeprint(struct tnode *);
int getword(char *,int);
struct tnode *talloc(void);
char *strup(char *);

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 *addtree(struct tnode *p,char *w)
{
    int cond;
    if(p==NULL)
    {
        p = talloc();
        p->word=strdup(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
        p->right = addtree(p->right,w);
    return p;
}

struct tnode *talloc(void)
{
    return (struct tnode *)malloc(sizeof(struct tnode));
}

char *strup(char *s)
{
    char *p;
    p=(char *)malloc(strlen(s)+1);
    if(p!=NULL)
        strcpy(p,s);
    return p;
}

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


int getword(char *word,int lim)
{
    char *w = word;
    int c;
    while(isspace (c = getchar()))
        ;
    if(c!=EOF)
        *w++ = c;
    if(!isalpha(c))
    {
        *w = '\0';
        return c;
    }
    for(;--lim>0;w++)
        if(!isalnum(*w = getchar()))
        {
            //ungetc(w);
            *w = '\0';
            break;
        }
    *w = '\0';
    return word[0];
}