Standard C++ Library Class Reference

Complexity
At most ((last1 - first1) + (last2 - first2)) * 2 -1 comparisons are performed.
Example
//
// includes.cpp
//
#include <algorithm>
#include <set>
#include <iostream.h>
int main()
{
//Initialize some sets
int a1[10] = {1,2,3,4,5,6,7,8,9,10};
int a2[6] = {2,4,6,8,10,12};
int a3[4] = {3,5,7,8};
set<int, less<int> > all(a1, a1+10), even(a2, a2+6),
small(a3,a3+4);
//Demonstrate includes
cout << "The set: ";
copy(all.begin(),all.end(),
ostream_iterator<int>(cout," "));
bool answer = includes(all.begin(), all.end(),
small.begin(), small.end());
cout << endl
<< (answer ? "INCLUDES " : "DOES NOT INCLUDE ");
copy(small.begin(),small.end(),
ostream_iterator<int>(cout," "));
answer = includes(all.begin(), all.end(),
even.begin(), even.end());
cout << ", and" << endl
<< (answer ? "INCLUDES" : "DOES NOT INCLUDE ");
copy(even.begin(),even.end(),
ostream_iterator<int>(cout," "));
cout << endl << endl;
return 0;
}
Output :
The set: 1 2 3 4 5 6 7 8 9 10
INCLUDES 3 5 7 8 , and
DOES NOT INCLUDE 2 4 6 8 10 12