Ordinamento libri (struct)

/*
Studente : Scia Massimiliano
Classe : 3IC
Data : 19/03/2012  16:19
Nome del file : ordinamento libri
*/

#include <iostream>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cctype>
#include <windows.h>
#include <fstream>
#include <time.h>
#include <string>
#include <stdio.h>
#define N 100

using namespace std;

/*void struct_swap(book *a, book *b){
    book temp;
    temp.price=a->price;
    a->price=b->price;
    b->price=temp.price;
}//struct_swap*/

struct book{
    float price;
    string title;
    string author;
};//book

void bg_col(){
    system("color 70");
}

void end(void){
    fflush(stdin);
    cout<<"\n\nPremere Invio per continuare.";
    getchar();
}//end

int dim(){
    int n;
    cout<<"\nQuanti libri vuoi inserire? ";
    cin>>n;
    return n;
}//dim

book books_info(){
    book b;
    fflush(stdin);
    cout<<"\nAutore/i: ";
    getline(cin,b.author);
    fflush(stdin);
    cout<<"\nTitolo: ";
    getline(cin,b.title);
    fflush(stdin);
    cout<<"\nPrezzo: ";
    cin>>b.price;
    fflush(stdin);
    return b;
}//books_info

void books(book b[], int n){
    cout<<"\n\n";
    for(int i=0;i<n;i++){
        cout<<"\n\t\tLibro "<<i+1<<" :\n";
        b[i]=books_info();
    }//for
}//books

void sort_by_price(book b[], int n){
    for(int i=0;i<n;i++)
        for(int j=i+1;j<n;j++)
            if(b[i].price>b[j].price)
                swap(b[i],b[j]);
}//sort_by_price

void sort_by_title(book b[], int n){
    for(int i=0;i<n;i++)
        for(int j=i+1;j<n;j++)
            if(b[i].title.compare(b[j].title)>0)
                swap(b[i],b[j]);
}//sort_by_title

void sort_by_author(book b[], int n){
    for(int i=0;i<n;i++)
        for(int j=i+1;j<n;j++)
            if(b[i].author.compare(b[j].author)>0)
                swap(b[i],b[j]);
}//sort_by_author

void visualize(book b[] , int n){
    cout<<"\n\nLe informazioni riguardanti i libri sono:\n";
    for(int i=0;i<n;i++){
        cout<<"\n\nAutore/i: "<<b[i].author;
        cout<<"\n\nTitolo: "<<b[i].title;
        cout<<"\n\nPrezzo: "<<b[i].price;
    }//for
}//visualize

void visualize_p(book b[] , int n){
    cout<<"\n\nOrdinamento per prezzo:\n";
    for(int i=0;i<n;i++){
        cout<<"\n\nAutore/i: "<<b[i].author;
        cout<<"\n\nTitolo: "<<b[i].title;
        cout<<"\n\nPrezzo: "<<b[i].price;
    }//for
}//visualize

void visualize_t(book b[] , int n){
    cout<<"\n\nOrdinamento per titolo:\n";
    for(int i=0;i<n;i++){
        cout<<"\n\nAutore/i: "<<b[i].author;
        cout<<"\n\nTitolo: "<<b[i].title;
        cout<<"\n\nPrezzo: "<<b[i].price;
    }//for
}//visualize

void visualize_a(book b[] , int n){
    cout<<"\n\nOrdinamento per autore:\n";
    for(int i=0;i<n;i++){
        cout<<"\n\nAutore/i: "<<b[i].author;
        cout<<"\n\nTitolo: "<<b[i].title;
        cout<<"\n\nPrezzo: "<<b[i].price;
    }//for
}//visualize

int main(){
    book biblioteca[N];
    bg_col();
    int n=dim();
    books(biblioteca,n);
    visualize(biblioteca,n);
    sort_by_price(biblioteca,n);
    visualize_p(biblioteca,n);
    sort_by_title(biblioteca,n);
    visualize_t(biblioteca,n);
    sort_by_author(biblioteca,n);
    visualize_a(biblioteca,n);
    end();
    return 0;
}//main