#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include "string.h"

typedef struct
{
    char nome[30];
    char cognome[30];
}

element; /* DEFINIZIONE */
typedef int boolean; /* DEFINIZIONE */

typedef struct list_element {
    element value;
    struct list_element *next;
} item;

typedef item* list;
boolean isLess(element, element);
boolean isEqual(element, element);
element copy(element e);
element getElement(void);

void printElement(element);
/* ---- PRIMITIVE ---- */
list emptylist(void);
boolean empty(list);
element head(list);
list tail(list);
list cons(element, list);
/* ---- NON PRIMITIVE ---- */
void showlist(list);

boolean isEqual(element e1, element e2) {
    if (strcmp(e1.cognome, e2.cognome) == 0
        && strcmp(e1.nome, e2.nome) == 0)
        return 1;
    else return 0;
}
boolean isLess(element e1, element e2) {
    if (strcmp(e1.cognome, e2.cognome) < 0 || (strcmp(e1.cognome, e2.cognome) == 0 &&
        strcmp(e1.nome, e2.nome) < 0))
        return 1;
    else return 0;
}

element copy(element e){
 element el;
 el=e;
return el;
}

element getElement(){
 element el;
 printf("Cognome: ");
 scanf("%s", el.cognome);
 printf("Nome: ");
 scanf("%s", el.nome);
 return el;
}

void printElement(element el){
 printf("\nCognome: %s, Nome: %s", el.cognome, el.nome);
}

list emptylist() {
 return NULL;
 }

boolean empty(list l) {
 return (l==NULL);
 }

element head(list l) {
 if (empty(l)) abort();
 else
 return l->value;
}

list tail(list l) {
 if (empty(l)) abort();
 else
     return l->next;
}

list cons(element e, list l) {
    list t;
    t = (list)malloc(sizeof(item));
    t->value = copy(e);
    t->next = l;
    return t;
}

void showlist(list l) {
    printf("Elenco Persone");
    while (!empty(l)) {
        printElement(head(l));
        l = tail(l);
        //if (!empty(l)) printf(", ");
    }
    printf("\n");
}

list insord(element e, list l) {
    list t;
    if (empty(l) || !isLess(head(l), e)) {
        t = cons(e, l);
        //t->next = l;
        return t;
    }
    return cons(head(l), insord(e, tail(l)));
}

list insord2(element e, list l) {
    list l1 = NULL, root = l;
    list t;
    t = cons(e, l);
    if (empty(l) || !isLess(head(l), e)) {
        return t;
    }
    while (!empty(l) && isLess(head(l), e)) {
        l1 = l;
        l = tail(l);
    }
    l1->next = t;
    t->next = l;
    return root;
}

void contaOmonimi(list l) {
    int n = 0;
    element e1;
    if (empty(l)) return;
    do {
        e1 = head(l);
        l = tail(l);
        if (!empty(l) && isEqual(head(l), e1)) {
            n++;
            while (!empty(l) && isEqual(head(l), e1))
                l = tail(l);
        }
    } while (!empty(l));
    printf("Gli omonimi sono: %d", n);
}

void main(void) {
    list l1 = emptylist();
    element el;
    int scelta;
    do {
        printf("\nIntrodurre Persona:\n");
        el = getElement();
        l1 = insord2(el, l1);
        printf("\n 0 per terminare, 1 per continuare:\n");
        scanf("%d", &scelta);
        //getch();
    } while (scelta == 1); /* condiz. arbitraria */
    showlist(l1);
    contaOmonimi(l1);
    getchar();
    getchar();
}