C++/Map Multimap/map search
Содержание
search for all occurrences of key
<source lang="cpp">
- include <algorithm>
- include <functional>
- include <iomanip>
- include <iostream>
- include <map>
- include <string>
- include <utility>
- include <vector>
using namespace std; class PC {
public:
enum PC_type { Dell, HP, IBM, Compaq };
PC( PC_type appliance = Dell, int model = 220,
int serial = 0 );
bool operator<( const PC& rhs ) const;
PC_type appliance() const;
int model() const;
string name() const;
void print() const;
int serial() const;
private:
PC_type appliance_;
int model_;
int serial_;
}; inline PC::PC( PC::PC_type appliance, int model,
int serial ) : appliance_( appliance ), model_( model ), serial_( serial )
{} // empty inline bool PC::operator<( const PC& rhs ) const { return appliance() < rhs.appliance() ||
( appliance() == rhs.appliance() && model() < rhs.model() );
} inline PC::PC_type PC::appliance() const { return appliance_; } inline int PC::model() const { return model_; } string PC::name() const {
string what;
switch( appliance() )
{
case Dell: what = "Dell"; break;
case HP: what = "HP"; break;
case IBM: what = "IBM"; break;
case Compaq: what = "Compaq"; break;
default: what = "Unknown appliance"; break;
}
return what;
} inline void PC::print() const {
char oldfill = cout.fill();
cout << name() << " - Model "
<< model() << ", Serial number "
<< serial() << endl;
} inline int PC::serial() const { return serial_; } bool greater_model( const pair<PC::PC_type,PC> p,int min_model ); int main( ) {
const PC::PC_type kind[] = { PC::IBM,PC::IBM, PC::Dell, PC::HP,PC::HP, PC::HP };
const int num_appliances = 3;
vector<PC> v;
for( int i = 0; i < num_appliances; ++i )
v.push_back( PC( kind[i], i, i ) );
map<int,PC> sold;
transform( kind, kind+num_appliances, v.begin(),inserter( sold, sold.end() ),make_pair<int,PC> );
map<int,PC>::const_iterator sold_end = sold.end();
// work with a multimap. key is appliance type, value is PC
typedef multimap<PC::PC_type,PC> PC_multimap_type;
PC_multimap_type stock;
const PC desired( PC::HP );
// load the appliances into the multimap
transform( kind, kind+num_appliances, v.begin(),inserter( stock, stock.end() ), make_pair<PC::PC_type,PC> );
PC_multimap_type::const_iterator stock_end = stock.end();
// search for first occurrence of key
PC_multimap_type::const_iterator spot = stock.find( desired.appliance() );
if( spot != stock_end )
spot->second.print();
else
cout << "Don"t have a " << desired.name() << " in stock\n";
} inline bool greater_model( const pair<PC::PC_type,PC> p,int min_model ) { return p.second.model() >= min_model; }
</source>
search for all occurrences of value
<source lang="cpp">
- include <algorithm>
- include <functional>
- include <iomanip>
- include <iostream>
- include <map>
- include <string>
- include <utility>
- include <vector>
using namespace std; class PC {
public:
enum PC_type { Dell, HP, IBM, Compaq };
PC( PC_type appliance = Dell, int model = 220,
int serial = 0 );
bool operator<( const PC& rhs ) const;
PC_type appliance() const;
int model() const;
string name() const;
void print() const;
int serial() const;
private:
PC_type appliance_;
int model_;
int serial_;
}; inline PC::PC( PC::PC_type appliance, int model,int serial )
: appliance_( appliance ), model_( model ), serial_( serial )
{} // empty inline bool PC::operator<( const PC& rhs ) const { return appliance() < rhs.appliance() ||
( appliance() == rhs.appliance() && model() < rhs.model() );
} inline PC::PC_type PC::appliance() const { return appliance_; } inline int PC::model() const { return model_; } string PC::name() const {
string what;
switch( appliance() )
{
case Dell: what = "Dell"; break;
case HP: what = "HP"; break;
case IBM: what = "IBM"; break;
case Compaq: what = "Compaq"; break;
default: what = "Unknown appliance"; break;
}
return what;
} inline void PC::print() const {
char oldfill = cout.fill();
cout << name() << " - Model "
<< model() << ", Serial number "
<< serial() << endl;
} inline int PC::serial() const { return serial_; } bool greater_model( const pair<PC::PC_type,PC> p,int min_model ); int main( ) {
const PC::PC_type kind[] = { PC::IBM,PC::Dell,PC::HP};
const int num_appliances = 3;
vector<PC> v;
for( int i = 0; i < num_appliances; ++i )
v.push_back( PC( kind[i], i, i ) );
map<int,PC> sold;
transform( kind, kind+num_appliances, v.begin(),inserter( sold, sold.end() ),make_pair<int,PC> );
map<int,PC>::const_iterator sold_end = sold.end();
// work with a multimap. key is appliance type, value is PC
typedef multimap<PC::PC_type,PC> PC_multimap_type;
PC_multimap_type stock;
const PC desired( PC::HP );
// load the appliances into the multimap
transform( kind, kind+num_appliances, v.begin(),inserter( stock, stock.end() ), make_pair<PC::PC_type,PC> );
PC_multimap_type::const_iterator stock_end = stock.end();
// search for all occurrences of value
cout << min_model << endl;
bool found = false;
for( spot = stock.begin(); spot != stock_end; ++spot )
if( greater_model( *spot, min_model ) ){
found = true;
spot->second.print();
}
if( !found )
cout << "No appliance with model number at least " << min_model << endl;
} inline bool greater_model( const pair<PC::PC_type,PC> p,int min_model ) { return p.second.model() >= min_model; }
</source>
search for first occurrence of value with find_if
<source lang="cpp">
- include <algorithm>
- include <functional>
- include <iomanip>
- include <iostream>
- include <map>
- include <string>
- include <utility>
- include <vector>
using namespace std; class PC {
public:
enum PC_type { Dell, HP, IBM, Compaq };
PC( PC_type appliance = Dell, int model = 220,
int serial = 0 );
bool operator<( const PC& rhs ) const;
PC_type appliance() const;
int model() const;
string name() const;
void print() const;
int serial() const;
private:
PC_type appliance_;
int model_;
int serial_;
}; inline PC::PC( PC::PC_type appliance, int model,
int serial ) : appliance_( appliance ), model_( model ), serial_( serial )
{} // empty inline bool PC::operator<( const PC& rhs ) const { return appliance() < rhs.appliance() ||
( appliance() == rhs.appliance() && model() < rhs.model() );
} inline PC::PC_type PC::appliance() const { return appliance_; } inline int PC::model() const { return model_; } string PC::name() const {
string what;
switch( appliance() )
{
case Dell: what = "Dell"; break;
case HP: what = "HP"; break;
case IBM: what = "IBM"; break;
case Compaq: what = "Compaq"; break;
default: what = "Unknown appliance"; break;
}
return what;
} inline void PC::print() const {
char oldfill = cout.fill();
cout << name() << " - Model "
<< model() << ", Serial number "
<< serial() << endl;
} inline int PC::serial() const { return serial_; } bool greater_model( const pair<PC::PC_type,PC> p,int min_model ); int main( ) {
const PC::PC_type kind[] = { PC::IBM,PC::Dell,PC::HP};
const int num_appliances = 3;
vector<PC> v;
for( int i = 0; i < num_appliances; ++i )
v.push_back( PC( kind[i], i, i ) );
map<int,PC> sold;
transform( kind, kind+num_appliances, v.begin(),inserter( sold, sold.end() ),make_pair<int,PC> );
map<int,PC>::const_iterator sold_end = sold.end();
// work with a multimap. key is appliance type, value is PC
typedef multimap<PC::PC_type,PC> PC_multimap_type;
PC_multimap_type stock;
const PC desired( PC::HP );
// load the appliances into the multimap
transform( kind, kind+num_appliances, v.begin(),inserter( stock, stock.end() ), make_pair<PC::PC_type,PC> );
PC_multimap_type::const_iterator stock_end = stock.end();
// search for first occurrence of value
const int min_model = 221;
spot = find_if( stock.begin(), stock.end(), bind2nd( ptr_fun( greater_model ), min_model ) );
cout << min_model;
if( spot != stock_end )
spot->second.print();
else
cout << "No appliance with model at least than " << min_model
<< endl;
} inline bool greater_model( const pair<PC::PC_type,PC> p,int min_model ) { return p.second.model() >= min_model; }
</source>
search for last occurrence of value
<source lang="cpp">
- include <algorithm>
- include <functional>
- include <iomanip>
- include <iostream>
- include <map>
- include <string>
- include <utility>
- include <vector>
using namespace std; class PC {
public:
enum PC_type { Dell, HP, IBM, Compaq };
PC( PC_type appliance = Dell, int model = 220,
int serial = 0 );
bool operator<( const PC& rhs ) const;
PC_type appliance() const;
int model() const;
string name() const;
void print() const;
int serial() const;
private:
PC_type appliance_;
int model_;
int serial_;
}; inline PC::PC( PC::PC_type appliance, int model,
int serial ) : appliance_( appliance ), model_( model ), serial_( serial )
{} // empty inline bool PC::operator<( const PC& rhs ) const { return appliance() < rhs.appliance() ||
( appliance() == rhs.appliance() && model() < rhs.model() );
} inline PC::PC_type PC::appliance() const { return appliance_; } inline int PC::model() const { return model_; } string PC::name() const {
string what;
switch( appliance() )
{
case Dell: what = "Dell"; break;
case HP: what = "HP"; break;
case IBM: what = "IBM"; break;
case Compaq: what = "Compaq"; break;
default: what = "Unknown appliance"; break;
}
return what;
} inline void PC::print() const {
char oldfill = cout.fill();
cout << name() << " - Model "
<< model() << ", Serial number "
<< serial() << endl;
} inline int PC::serial() const { return serial_; } bool greater_model( const pair<PC::PC_type,PC> p,int min_model ); int main( ) {
const PC::PC_type kind[] = { PC::IBM,PC::Dell,PC::HP};
const int num_appliances = 3;
vector<PC> v;
for( int i = 0; i < num_appliances; ++i )
v.push_back( PC( kind[i], i, i ) );
map<int,PC> sold;
transform( kind, kind+num_appliances, v.begin(),inserter( sold, sold.end() ),make_pair<int,PC> );
map<int,PC>::const_iterator sold_end = sold.end();
// work with a multimap. key is appliance type, value is PC
typedef multimap<PC::PC_type,PC> PC_multimap_type;
PC_multimap_type stock;
const PC desired( PC::HP );
// load the appliances into the multimap
transform( kind, kind+num_appliances, v.begin(),inserter( stock, stock.end() ), make_pair<PC::PC_type,PC> );
PC_multimap_type::const_iterator stock_end = stock.end();
// search for last occurrence of value
multimap<PC::PC_type,PC>::reverse_iterator j = find_if( stock.rbegin(), stock.rend(),bind2nd( ptr_fun( greater_model ), min_model ) );
cout << "\nLAST APPLIANCE WITH MODEL AT LEAST " << min_model << endl;
if( j != stock.rend() )
j->second.print();
else
cout << "No appliance with model number at least " << min_model << endl;
} inline bool greater_model( const pair<PC::PC_type,PC> p,int min_model ) { return p.second.model() >= min_model; }
</source>
