в 14:21, 25 мая 2010

2010-05-25T14:21:17Z

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2010-05-25T10:29:38Z

1 версия: Импорт контента...

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==assign a list to a vector==

<source lang="cpp">#include <list>
#include <vector>
#include <iostream>
using namespace std;
template <class T>
void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
std::cout << *i << endl;
}
}
int main( )
{
const double data[] = { 3.14, 2.78, 1.51, 7.66, 9.65 };
list<double> original( data, data + sizeof( data ) / sizeof( data[0] ) );
vector<double> vector_data( 3, 3.33 );
list<double> list_data( 4, 4.44 );
// show results
print( original );
print( vector_data );
print( list_data );
// assign a list to a list
list_data = original;
// assign a list to a vector
vector_data.assign( original.begin(), original.end() );
print( list_data );
print( vector_data );

}</source>

==create an empty vector of int"s and assign a list of doubles to it==

<source lang="cpp">#include <list>
#include <vector>
#include <iostream>
using namespace std;
template <class T>
void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
std::cout << *i << endl;
}
}
int main( )
{
const double data[] = { 3.14, 2.78, 1.51, 7.66, 9.65 };
list<double> original( data, data + sizeof( data ) / sizeof( data[0] ) );
vector<double> vector_data( 3, 3.33 );
list<double> list_data( 4, 4.44 );
// show results
print( original );
print( vector_data );
print( list_data );
// assign a list to a list
list_data = original;
// create an empty vector of int"s and assign a list of doubles to it
vector<int> v;
v.assign( original.begin(), original.end() );
// show results
print( list_data );
print( v );
}</source>

==make a vector from a list with vector_copy==

<source lang="cpp">#include <iomanip>
#include <iostream>
#include <list>
#include <vector>
using namespace std;
template <class T>
void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
std::cout << *i << endl;
}
}
int main( )
{
const int data[] = { 1, 1, 2, 3, 5 };
list<int> original( data,data + sizeof( data ) / sizeof( data[0] ) );
// make a vector from a list
vector<int> vector_copy( original.begin(), original.end() );
// show results
print( original);
print( vector_copy);
}</source>

==Transfer vector to a list and remove all negative numbers with bind2nd and less==

<source lang="cpp">#include <algorithm>
#include <cmath>
#include <functional>
#include <iostream>
#include <list>
#include <numeric>
#include <vector>
using namespace std;
template <class T>
void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
std::cout << *i << endl;
}
}
int main( )
{
const float a[] = { 1, -2.3, 4.5, -6.7, 8.9, 10.2};
// create and initialize vector with above data
vector<float> data( a,a + sizeof( a ) / sizeof( a[0] ) );
cout << "DATA VECTOR HAS " << data.size() << " ELEMENTS\n";
print( data );
// transfer to a list and remove all negative numbers
list<float> l( data.begin(), data.end() );
cout << "\nSize of list before calling remove_if: "<< l.size() << endl;
l.remove_if( bind2nd( less<float>(), 0 ) );
cout << "Size of list after calling remove_if: " << l.size() << endl;
print( l );
}</source>

==Vector of list of strings==

<source lang="cpp">#include <list>
#include <vector>
#include <string>
#include <algorithm>
#include <iterator>
#include <fstream>
#include <iostream>
#include <sstream>
using namespace std;
list<string>
getTotalEnrollment(const vector<list<string> >& classLists,const list<string>& droppedStudents)
{
list<string> allStudents;
for (size_t i = 0; i < classLists.size(); ++i) {
allStudents.insert(allStudents.end(), classLists[i].begin(),classLists[i].end());
}
allStudents.sort();
allStudents.unique();
for (list<string>::const_iterator it = droppedStudents.begin();
it != droppedStudents.end(); ++it) {
allStudents.remove(*it);
}
return (allStudents);
}
void readStudentList(list<string> &students, ifstream &istr)
{
string name;
while (getline(istr, name)) {
cout << "Read name " << name << endl;
students.push_back(name);
}
}
void readCourseLists(vector<list<string> > &lists){
for(int i = 1; ; i++) {
ostringstream ostr;
ostr << "course" << i << ".txt";
ifstream istr(ostr.str().c_str());
if (!istr) {
cout << "Failed to open " << ostr.str() << endl;
break;
}
list<string> newList;
readStudentList(newList, istr);
lists.push_back(newList);
}
}
void readDroppedStudents(list<string> &students){
ifstream istr("dropped.txt");
readStudentList(students, istr);
}
int main(int argc, char **argv)
{
vector<list<string> > courseLists;
list<string> droppedStudents;
readCourseLists(courseLists);
readDroppedStudents(droppedStudents);
list<string> finalList = getTotalEnrollment(courseLists, droppedStudents);
copy(finalList.begin(), finalList.end(), ostream_iterator<string>(cout, "\n"));
}</source>

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