streecmp/streecmp.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "streecmp.h"

int strs_cnt = 0; 

struct nod *allocnod(void) {
    struct nod *nod = (struct nod *) calloc(1, sizeof(struct nod));
    if (nod == NULL) {
        return NULL;
    }

    nod->pool = (struct nod **) calloc(256, sizeof(struct nod *));
    if (nod->pool == NULL) {
        free(nod); 
        return NULL;
    }

    return nod;
}

struct nod *mknod(struct nod *nod, int loc) {
    if (nod == NULL) {
        return allocnod();
    }

    if (nod->pool == NULL) {
        return NULL;
    }

    nod->pool_size++; 
    nod->pool[loc] = allocnod();
    
    return nod->pool[loc];
}

int mkstr(struct nod *nod, char *str) {
    struct nod *target = nod->pool[*str];
    if (target != NULL) {
        return mkstr(target, str+1);
    }

    struct nod *new = mknod(nod, *str);
    if (new == NULL) {
        return -1;
    }

    new->val.cval = *str;
    if (*str != '\0') {
        return mkstr(new, str+1);
    }

    strs_cnt++;
    new->val.ival = strs_cnt;
    return strs_cnt;
}

int gentree(struct nod *nod, char *strs) {
    char *strs_cpy = strdup(strs);
    if (strs_cpy == NULL) {
        return -1;
    }

    for (char *tok = strtok(strs_cpy, "\n"); tok != NULL; tok
            = strtok(NULL, "\n")) {
        int ret = mkstr(nod, tok);
        if (ret < 0) {
            return -1;
        }
    }

    return 0;
}

int streecmp(struct nod *nod, char *str) {
    struct nod *target = nod->pool[*str];
    if (target == NULL) {
        return 0;
    }

    if (target->val.cval == '\0') {
        return target->val.ival;
    }

    return streecmp(target, str+1);
}