void emphasize(char* s) {
    char* t = (char*)malloc(sizeof(char) * (strlen(s) + 1));
    unsigned int i = 0;

    while (s[i]) {
        if (s[i] == '.') {
            t[i] = '!';
        } else {
            t[i] = s[i];
        }
        i++;
    }
    t[i] = '\0';

    printf("t = %s", t);
    free(t);
}