Re: I'm a newbie. Is this code ugly?
In message <4b57269b$0$1132$4fafbaef@reader1.news.tin.it>, io_x
<a@b.c.invalid> trolled
"Richard Herring" <junk@[127.0.0.1]> ha scritto nel messaggio
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In message <4b56d0c2$0$828$4fafbaef@reader5.news.tin.it>, io_x
<a@b.c.invalid>
writes
"gert" <27hiro@googlemail.com> ha scritto nel messaggio
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I'm using a class which can sinksort an array of it's own objects and
an example T class, which can have names and stuff...
I was in doubt about what to do about nearly any line, so I would love
any of your recommendations...
what about this?
Horrible.
This code works, after a fashion, because those strings are all
literals. What
would happen if you were reading values from a file?
no problem, i make local copy
Still horrible.
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#define R return
Using macros to represent language keywords is inexcusable obfuscation.
Are you J*ff R*lf?
using namespace std;
char* faiMemCopia(char* v)
Why are you (badly) reinventing strcpy() ?
{int i, n;
char *p;
if(v==0) R 0;
n=strlen(v);
if(n<=0) R 0;
Why? There's nothing intrinsically wrong with a zero-length string.
p=(char*) malloc(n+1);
if(p==0) R 0;
for(i=0; i<n; ++i)
p[i]=v[i];
p[i]=0;
R p;
}
class T{
public:
char *num_, *surname_;
char *key_;
T(){num_=0; surname_=0; key_=0;}
int alloca(char *num, char *key, char *surname)
This sets up the class invariant. Put it in a constructor.
{num_=0; surname_=0; key_=0;
num_=faiMemCopia(num);
if(num_==0) return 0;
surname_=faiMemCopia(surname);
if(surname==0)
{la0:
free(num_); num_=0;
R 0;
}
key_=faiMemCopia(key);
if(key_==0){free(surname_); surname_=0;
goto la0;
Nice spaghetti.
}
R 1;
}
void Tfree(void)
{free(num_); free(key_); free(surname_);
num_=0; surname_=0; key_=0;
}
This releases resources. Put it in a destructor.
};
class ArrArrT{
public:
T** v;
int n;
int sz;
ArrArrT(){v=0; n=0; sz=0;}
int add(char *num, char *key, char *surname)
{if(sz<=n){T **p;
p=(T**)realloc(v, (n+128)*sizeof(T*));
if(p==0) R 0;
sz=n+128;
Still no explanation for those magic 128s.
v =p;
}
v[n]=(T*) malloc(sizeof(T));
if(v[n]==0) R 0;
if( v[n]->alloca(num, key, surname)==0)
R 0;
++n;
R 1;
}
void sort()
{int i, hit=1, len=n;
T *temp;
while(len>1&&hit)
{len--;
hit=0;
for(i=0; i<len; ++i)
if(strcmp(v[i]->key_,v[i+1]->key_)>0)
{temp=v[i]; v[i]=v[i+1]; v[i+1]=temp; hit=1;}
}
}
~ArrArrT(){int i=n;
for(--i; i>=0; --i)
{v[i]->Tfree();
free(v[i]);
}
free(v);
}
T& operator[](int i)
{static T no;
if(i<0||i>=n)
{cout << "\n\aIndice fuori dei limiti\n"; R no;}
R *(v[i]);
}
};
int main(void)
{int i;
ArrArrT a;
i=1;
i*=a.add("a","Mann","Thomas");
i*=a.add("b","Satie","Erik");
i*=a.add("c","Goldfarb","Sarah");
i*=a.add("d","Ravel","Maurice");
i*=a.add("e","Hideyuki","Tanaka");
i*=a.add("f","Twain","Mark");
if(i==0) {cout << "Memory error\n"; R 0;}
a.sort();
for(i=0; i<a.n; ++i)
cout <<a.v[i]->surname_<<"\t"<<a.v[i]->key_<<"\n";
for(i=0; i<a.n; ++i)
cout <<a[i].surname_<<"\t"<<a[i].key_<<"\n";
R 0;
}
Sheesh.
#include <string>
#include <vector>
#include <algorithm>
#include <ostream>
#include <iostream>
#include <iterator>
using namespace std; // SSM
struct Artist
{
string surname_, firstname_;
Artist(string const & surname, string const & firstname)
: surname_(surname), firstname_(firstname) {}
};
ostream & operator<<(ostream & s, Artist const & t)
{ return s << t.firstname_ << ' ' << t.surname_; }
struct CompareSurname
{
bool operator()(Artist const & a, Artist const & b) const
{ return a.surname_ < b.surname_; }
};
int main()
{
vector<Artist> artists;
artists.push_back(Artist("Mann", "Thomas"));
artists.push_back(Artist("Satie", "Erik"));
/* etc... */
sort(artists.begin(), artists.end(), CompareSurname());
copy(artists.begin(), artists.end(), ostream_iterator<Artist>(cout, "\n"));
}
--
Richard Herring