Collaborazione Romano/Romano

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

#define MAX_LEN 15

int main(){
    int i, j, k = 0, presente = 0;
    char c;
    char **testo = NULL;

    FILE* fp = fopen("diario.txt", "r");
    if(fp == NULL){
        printf("Errore lettura file\n");
        return -1;
    }

    for(i = 0; !feof(fp); i++){
        c = fgetc(fp);
        char *buffer = malloc(20*sizeof(char));
        while((c >= 65 && c <= 90) || (c >= 97 && c <= 122) || (c >= 48 && c <= 57)){
            testo = (char **)realloc(testo, (i+1)*sizeof(char*));
            testo[k] = (char *)malloc(20*sizeof(char));
            for(j = 0; ((c >= 65 && c <= 90) || (c >= 97 && c <= 122) || (c >= 48 && c <= 57)); j++){
                buffer[j] = c;
                c = fgetc(fp);
            }
            strcpy(testo[k], buffer);
            k++;
        }
    }
    fclose(fp);

    for(int count = 1; count < MAX_LEN; count++){
        for(int index = 0; index < k; index++){
            if(strlen(testo[index]) == count)
                presente++;
        }
        if(presente != 0)
            printf("Parole lunghe %d caratteri: %d\n", count, presente);
        presente = 0;
    }
}