Simple C Hangman game

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

#define LENOF(A) (int)(sizeof(A)/sizeof(*A))

int main(){
    char *word;
    char *words[]= {"elephant", "cook", "balling", "monkey", "eggs", "pacifist", "sick", "cool", "dog", "city"};

    char *guessed;
    char *guessed_before;

    int i;
    int guesses_wrong = 0;

    int len;
    int max_len = 0;
    int word_len;

    srand(time(NULL));
    word = words[rand() % (LENOF(words))];

    for(i = 0; i < LENOF(words); i++) {
        len = strlen(words[i]);                         /* finds the longest word in the array */
        if(len > max_len) max_len = len;
    }

    guessed = malloc(sizeof(char) * max_len + 1);
    if(!guessed) {perror("malloc"); return 1;}
    guessed_before = malloc(sizeof(char) * max_len + 1);
    if(!guessed) {perror("malloc"); return 1;}

    printf("This is a hangman game, even though there is no hanging men around here.\n");
    printf("You only have 3 chances before the game ends.\n");
    printf("Also, every duplicate counts as a wrong guess! Have fun!\n\n");

    word_len = strlen(word);

    for(i = 0; i < word_len; i++){                      /* fills guessed array with underscores */
        guessed[i] = '_';
    }
    guessed[word_len] = '\0';

    printf("%s\n", guessed);

    while(strcmp(word,guessed) != 0){                   /* game over if over 3 fails */
        char letter;

        if(guesses_wrong > 2){
            printf("\nGame over!\nThe word was '%s'.\n", word);

            free(guessed);
            free(guessed_before);
            return 0;
        }
        printf("\nInput a letter:");
        scanf(" %c", &letter);

        strcpy(guessed_before, guessed);                /* generates before version of the array */
        for(i = 0; i < word_len; i++){
            if(word[i] == letter){
                guessed[i] = letter;                    /* if the letter is correct, replace underscore with it */
            }
        }
        printf("\n%s\n", guessed);

        if(strcmp(guessed_before, guessed) == 0){       /* if there was no change in guessed array, increase wrong count */
            guesses_wrong++;
            printf("\nYou have %d wrong guesses!\n", guesses_wrong);
        }
    }

    printf("\nCongratulations, you won!\n");

    free(guessed);
    free(guessed_before);
    return 0;
}