最終的に、プログラムは名前のリストをアルファベット順に出力し、その名前に関連付けられた追加の属性も表示します。つまり、出力画面は次のようになります。
Ares: Greek, fire, sword.
Freia: Norse, water, bow and arrow.
Poseidon: Greek, horses, ocean.
Thor: Norse, chariot, hammer.
Zeus: Greek, cloud, lightning.
繰り返しますが、このリストでは最初の名前はアルファベット順に並べられていますが、属性はそれらの横に印刷されています。int main( ) に関しては、これらの名前をどのように並べ替えて整理する必要があるのか わかりません。ソートする必要があるソートされていないリストがあります（これらの名前を正しい順序に追加/挿入する関数を使用）。
//
// This is a standard library support code to the chapters of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//
#ifndef STD_LIB_FACILITIES_GUARD
#define STD_LIB_FACILITIES_GUARD 1
#include <cmath>
#include <iostream>
#include <vector>
#include <stdexcept>
#include <string>
using namespace std;
//------------------------------------------------------------------------------
// Helper function to show an error message
inline void error(const string& errormessage)
{
throw runtime_error(errormessage);
}
//------------------------------------------------------------------------------
#endif // STD_LIB_FACILITIES_GUARD
//------------------------------------------------------------------------------
struct Link {
string name;
string mythology;
string vehicle;
string weapon;
Link* prev;
Link* succ;
Link(const string& n, const string& a, const string& b, const string&c,Link* p = 0,
Link* s = 0)
: name(n), mythology(a), vehicle(b), weapon(c), prev(p), succ(s) { }
};
Link* insert(Link* p, Link* n) // insert n before p; return n
{
if (n==0) return p;
if (p==0) return n;
n->succ = p; // p comes after n
if (p->prev) p->prev->succ = n;
n->prev = p->prev; // p's predecessor becomes n's predecessor
p->prev = n; // n becomes p's predecessor
return n;
}
void print_all(Link *p)
{
Link *current;
current = p;
while(current)
{
cout<<"For this link we have: \n";
cout<<"Name: "<<current->name<<".\n";
cout<<"Info1: "<<current->mythology<<".\n";
cout<<"Info2: "<<current->vehicle<<".\n";
cout<<"Info3: "<<current->weapon<<".\n";
current = current->succ;
}
}
Link * add_after_find(Link *p, Link *n,const string& s )
{ Link *current = 0;
current = p;
/* empty list */
if(p == 0)
{ cout<<"List is empty so string not found so not added after it. \n";
return 0;
}
/* DO WE NEED ONE LINK ONLY */
else if(p->succ == 0) /* one link only */
{
if(p->name == s)
{
/* add after link with s */
/* p in front */
p->succ = n;
n->prev = p;
p->prev = 0;
n->succ = 0;
return p;
} /* end of if names = */
else {
cout<<"String not found in link listed so not added. \n";
return p;
}
} /* end of one link */
else /* two or more links */
{
current = p;
while(current->succ)
{
if (s == current->name)
{
/* then n goes AFTER this link */
n->prev = current;
n->succ = current->succ;
current->succ = n;
return p;
} /* end of name matches */
else
{
current = current->succ;
}
}// end of while
/* if outside of while then we are at last link with a current -> name
so s not found */
cout<<"String is not found so not add after it. \n";
return p;
} // end of else 2 or more
} // end of function
int main()
{
Link*newlist = new Link("Thor","Norse","chariot","hammer");
newlist = add_after_find(newlist,new Link("Hera","Greek", "horse", "arrow"),"Thor");
newlist = add_after_find(newlist,new Link("Poseidon","Greek", "ocean", "trident"),"Freia");
newlist = add_after_find(newlist,new Link("Ares","Greek", "fire", "sword"),"Poseidon");
newlist = add_after_find(newlist,new Link("Zeus","Greek", "cloud", "lightning"),"Ares");
print_all(newlist);
cout<<"Now let's alphabetize these five gods.\n";
system("Pause");
return 0;
}