multiset_name.equal_range(key)

// CPP程序演示
// multiset::equal_range()函数
#include
using namespace std;
int main()
{
  
    multiset s;
  
    // 插入元素
    s.insert(1);
    s.insert(6);
    s.insert(2);
    s.insert(5);
    s.insert(3);
    s.insert(3);
    s.insert(5);
    s.insert(3);
  
    // 打印multiset元素
    cout << "The multiset elements are: ";
    for(auto it = s.begin(); it != s.end(); it++)
        cout << *it << " ";
  
    // 函数返回下限和上限
    auto it = s.equal_range(3);
    cout << "\nThe lower bound of 3 is " << *it.first;
    cout << "\nThe upper bound of 3 is " << *it.second;
  
    // 函数返回最后一个元素
    it = s.equal_range(10);
    cout << "\nThe lower bound of 10 is " << *it.first;
    cout << "\nThe upper bound of 10 is " << *it.second;
  
    // 函数返回大于0的元素所在的范围
    it = s.equal_range(0);
    cout << "\nThe lower bound of 0 is " << *it.first;
    cout << "\nThe upper bound of 0 is " << *it.second;
  
    return 0;
}

The multiset elements are: 1 2 3 3 3 5 5 6 
The lower bound of 3 is 3
The upper bound of 3 is 5
The lower bound of 10 is 8
The upper bound of 10 is 8
The lower bound of 0 is 1
The upper bound of 0 is 1

// CPP程序演示
// multiset::equal_range()函数
#include
using namespace std;
int main()
{
  
    multiset s;
  
    // 插入元素
    s.insert(1);
    s.insert(6);
    s.insert(2);
    s.insert(5);
    s.insert(3);
    s.insert(3);
    s.insert(5);
    s.insert(3);
  
    // 打印multiset元素
    cout << "The multiset elements are: ";
    for(auto it = s.begin(); it != s.end(); it++)
        cout << *it << " ";
  
    // 函数返回下限和上限
    auto it = s.equal_range(3);
    cout << "\nThe lower bound of 3 is " << *it.first;
    cout << "\nThe upper bound of 3 is " << *it.second;
  
    s.erase(it.first, it.second);
  
    // 删除范围后打印multiset元素
    cout << "\nThe multiset elements are: ";
    for(auto it = s.begin(); it != s.end(); it++)
        cout << *it << " ";
  
    return 0;
}

多重集合元素为：1 2 3 3 3 5 5 6
3的下界为3
3的上界为5
多重集合元素为：1 2 5 5 6