в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

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2010-05-25T10:27:43Z

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==Erase first element==

<source lang="cpp">

#include <iostream>
using std::cout;
using std::endl;
#include <vector> // vector class-template definition
#include <algorithm> // copy algorithm
#include <iterator> // ostream_iterator iterator
#include <stdexcept> // out_of_range exception
int main()
{
int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
std::vector< int > integers( array, array + 6 );
std::ostream_iterator< int > output( cout, " " );
integers.push_back( 2 );
integers.push_back( 3 );
integers.push_back( 4 );
cout << "Vector integers contains: ";
std::copy( integers.begin(), integers.end(), output );
// erase first element
integers.erase( integers.begin() );
cout << "\n\nVector integers after erasing first element: ";
std::copy( integers.begin(), integers.end(), output );

return 0;
}
/*
Vector integers contains: 1 2 3 4 5 6 2 3 4
Vector integers after erasing first element: 2 3 4 5 6 2 3 4
*/

</source>

==Remove(delete) all elements in the vector==

<source lang="cpp">

#include <iostream>
using std::cout;
using std::endl;
#include <vector> // vector class-template definition
#include <algorithm> // copy algorithm
#include <iterator> // ostream_iterator iterator
#include <stdexcept> // out_of_range exception
int main()
{
int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
std::vector< int > integers( array, array + 6 );
std::ostream_iterator< int > output( cout, " " );
integers.push_back( 2 );
integers.push_back( 3 );
integers.push_back( 4 );
cout << "Vector integers contains: ";
std::copy( integers.begin(), integers.end(), output );
// erase remaining elements
integers.erase( integers.begin(), integers.end() );
cout << "\nAfter erasing all elements, vector integers "
<< ( integers.empty() ? "is" : "is not" ) << " empty";
return 0;
}
/*
Vector integers contains: 1 2 3 4 5 6 2 3 4
After erasing all elements, vector integers is empty
*/

</source>

==Removes an element from an ordered vector==

<source lang="cpp">
#include <iostream>
#include <string>
#include <vector>
using namespace std;
void erase(vector<string>& v, int pos)
{
for (int i = pos; i < v.size() - 1; i++)
v[i] = v[i + 1];
v.pop_back();
}
void print(vector<string> v){
for (int i = 0; i < v.size(); i++)
cout << "[" << i << "] " << v[i] << "\n";
}
int main()
{
vector<string> staff(5);
staff[0] = "A";
staff[1] = "B";
staff[2] = "C";
staff[3] = "D";
staff[4] = "E";
print(staff);
int pos;
cout << "Remove which element? ";
cin >> pos;
erase(staff, pos);
print(staff);
return 0;
}

</source>

==Removes an element from an unordered vector==

<source lang="cpp">
#include <iostream>
#include <string>
#include <vector>
using namespace std;
void erase(vector<string>& v, int pos)
{
int last_pos = v.size() - 1;
v[pos] = v[last_pos];
v.pop_back();
}
void print(vector<string> v){
for (int i = 0; i < v.size(); i++)
cout << "[" << i << "] " << v[i] << "\n";
}
int main()
{
vector<string> staff(5);
staff[0] = "A";
staff[1] = "B";
staff[2] = "C";
staff[3] = "D";
staff[4] = "E";
print(staff);
int pos;
cout << "Remove which element? ";
cin >> pos;
erase(staff, pos);
print(staff);
return 0;
}

</source>

==Use unique_copy to remove duplicate words==

<source lang="cpp">

/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <iterator>
using namespace std;
int main()
{
vector<string> coll;
/* read all words from the standard input
* - source: all strings until end-of-file (or error)
* - destination: coll (inserting)
*/
copy (istream_iterator<string>(cin), // start of source
istream_iterator<string>(), // end of source
back_inserter(coll)); // destination
// sort elements
sort (coll.begin(), coll.end());
/* print all elements without duplicates
* - source: coll
* - destination: standard output (with newline between elements)
*/
unique_copy (coll.begin(), coll.end(), // source
ostream_iterator<string>(cout,"\n")); // destination
}
/*
asdf
as
asd
as
d
asd
as
a^CTerminate batch job (Y/N)? n
*/

</source>

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