Algorithm - equal_range()

원형)

//기본형
template <class ForwardIterator, class T>
  pair<ForwardIterator,ForwardIterator>
    equal_range (ForwardIterator first, ForwardIterator last, const T& val);
 
//사용자 정의형
template <class ForwardIterator, class T, class Compare>
  pair<ForwardIterator,ForwardIterator>
    equal_range (ForwardIterator first, ForwardIterator last, const T& val,
                  Compare comp);

의미)

[Iterator first, Iterator last)사이에 있는 모든 데이터들에 대한 subrange를 리턴합니다.

소스)

#include <iostream>
#include <algorithm>
#include <vector>
 
void print(std::vector<int> Target_Vector)
{
    for (std::vector<int>::iterator IterPos = Target_Vector.begin(); IterPos != Target_Vector.end(); ++IterPos)
        std::cout << *IterPos << " ";
    std::cout << std::endl;
}
void main() 
{
    std::vector<int> Vector = { 5,10,15,20,25,30 };
    std::pair<std::vector<int>::iterator, std::vector<int>::iterator> Pair;
    Pair = std::equal_range(Vector.begin(), Vector.end(), 5);
    print(Vector);
    std::cout << "Pair First -->" << *Pair.first << std::endl;
    std::cout << "Pair Second -->" << *Pair.second << std::endl;
}

내용)

first로 lower_bound(x,y,z)의 리턴값을, second로 upper_bound(x,y,z)의 리턴값을 가진 pair를 리턴합니다.

결과)