C++/Set Multiset/set
Содержание
Add elements in a list to a set
#include <iostream>
#include <cassert>
#include <list>
#include <string>
#include <set>
using namespace std;
int main()
{
string s("There is no distinctly native American criminal class");
list<char> list1(s.begin(), s.end());
// Put the characters in list1 into set1:
set<char> set1;
list<char>::iterator i;
for (i = list1.begin(); i != list1.end(); ++i)
set1.insert(*i);
set<char>::iterator j;
for (j = set1.begin(); j != set1.end(); ++j)
cout << *j;
return 0;
}
/*
ATacdehilmnorstvy
*/
Assigning sets to each other
#include <set>
#include <iostream>
#include <string>
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()
{
set<string> first;
first.insert("r");
first.insert("T");
first.insert("s");
cout << first.size() << endl;
set<string> second (first); // Copy constructor
second.insert("r");
second.insert("K");
second.insert("S");
second.insert("b");
cout << second.size() << endl;
set<string> third = first;
print(first);
print(second);
print(third);
set<string> set2(first);
set2.insert("l");
print(set2);
}
Create a set that contains list1 - list2
#include <iostream>
#include <list>
#include <algorithm>
using namespace std;
template<class InIter>
void show_range(const char *msg, InIter start, InIter end);
int main()
{
list<char> list1, list2, result(15);
list<char>::iterator res_end;
for(int i=0; i < 5; i++) {
list1.push_back("A"+i);
}
for(int i=3; i < 10; i++) {
list2.push_back("A"+i);
}
show_range("Contents of list1: ", list1.begin(), list1.end());
show_range("Contents of list2: ", list2.begin(), list2.end());
res_end = set_difference(list1.begin(), list1.end(),list2.begin(), list2.end(),result.begin());
show_range("list1 - list2: ", result.begin(), res_end);
return 0;
}
template<class InIter>
void show_range(const char *msg, InIter start, InIter end) {
InIter itr;
cout << msg << endl;
for(itr = start; itr != end; ++itr)
cout << *itr << endl;
}
Create sets with string elements
#include <set>
#include <iostream>
#include <string>
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()
{
set<string> first;
first.insert("r");
first.insert("T");
first.insert("s");
}
Declare a string set
#include <iostream>
#include <set>
#include <string>
using namespace std;
int main( ) {
set<string> setStr;
string s = "B";
setStr.insert(s);
s = "S";
setStr.insert(s);
s = "R";
setStr.insert(s);
s = "H";
setStr.insert(s);
for (set<string>::const_iterator p = setStr.begin( );p != setStr.end( ); ++p)
cout << *p << endl;
}
/*
B
H
R
S
*/
Read keyboard input to a set directly
/* 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 <string>
#include <algorithm>
#include <iterator>
#include <set>
using namespace std;
int main()
{
/* create a string set
* - initialized by all words from standard input
*/
set<string> coll((istream_iterator<string>(cin)),
istream_iterator<string>());
// print all elements
copy (coll.begin(), coll.end(),
ostream_iterator<string>(cout, "\n"));
}
/*
a b cd
^CTerminate batch job (Y/N)? n
*/
Use array to initialize a set
#include <iostream>
using std::cout;
using std::endl;
#include <set>
#include <algorithm>
#include <iterator> // ostream_iterator
int main()
{
double a[ 5 ] = { 2.1, 4.2, 9.5, 2.1, 3.7 };
std::set< double, std::less< double > > doubleSet( a, a + 5 );;
std::ostream_iterator< double > output( cout, " " );
cout << "doubleSet contains: ";
std::copy( doubleSet.begin(), doubleSet.end(), output );
cout << endl;
return 0;
}
/*
doubleSet contains: 2.1 3.7 4.2 9.5
*/