The C++ Standard Library consists of the header, <algorithm> which defines a collection of functions (principally designed to deal with a range of elements). includes() is a method in the STL that tests whether a sorted range includes another sorted range.
Syntax:
includes( iterator_begin1, iterator_end1, iterator_begin2, iterator_end2, comparator); //comparator is optional
Parameters: The includes() method accepts 5 parameters
- iterator_begin1, iterator_end1: Iterator to the initial and final position of first sorted sequence ( Note: the range is [iterator_begin1, iterator_end1) )
- iterator_begin2, iterator_end2: Iterator to the initial and final position of second sorted sequence ( Note: the range is [iterator_begin2, iterator_end2) )
- comparator: Binary function that accepts two elements in the range as arguments, and returns a value convertible to bool.
Return value: true if second range is included in the first range, false otherwise
Example of includes() method
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main () {
vector<int> v1;
v1.push_back(5);
v1.push_back(6);
v1.push_back(3);
v1.push_back(1);
v1.push_back(2);
vector<int> v2;
v2.push_back(3);
v2.push_back(1);
v2.push_back(2);
sort (v1.begin(),v1.end()); // 1 2 3 5 6
sort (v2.begin(),v2.end()); // 1 2 3
if(includes(v1.begin(), v1.end(), v2.begin(), v2.end()))
cout<<"V1 includes V2";
}
Output:
V1 includes V2
