C++ Set容器 集合运算

代码如下：

#include <set>
#include <string>
#include <algorithm>
#include <iostream>
int main(void)
{
    using namespace std;
    set<string> set_01;
    set<string> set_02;
    set<string> intersection_tmp;
    set<string> difference_tmp;
    set<string> set_union_tmp;
    set_01.insert("a");
    set_01.insert("b");
    set_01.insert("c");
    set_01.insert("d");
    set_01.insert("e");
    set_02.insert("a");
    set_02.insert("b");
    set_02.insert("c");
    set_02.insert("x");
    set_02.insert("y");

    cout << "Intersection:" << endl;

    set_intersection(
        set_01.begin(), set_01.end(),
        set_02.begin(), set_02.end(),
        insert_iterator<set<string>>(intersection_tmp, intersection_tmp.begin()));

    for (set<string>::iterator it = intersection_tmp.begin(); it != intersection_tmp.end(); it++)
    {
        cout << *it << endl;
    }

    cout << "Difference:" << endl;

    set_difference(
        set_01.begin(), set_01.end(),
        intersection_tmp.begin(), intersection_tmp.end(),
        insert_iterator<std::set<std::string>>(difference_tmp, difference_tmp.begin()));

    for (set<string>::iterator it = difference_tmp.begin(); it != difference_tmp.end(); it++)
    {
        cout << *it << endl;
    }

    cout << "Union:" << endl;

    set_union(
        set_01.begin(), set_01.end(),
        set_02.begin(), set_02.end(),
        insert_iterator<set<string>>(set_union_tmp, set_union_tmp.begin()));

    for (set<string>::iterator it = set_union_tmp.begin(); it != set_union_tmp.end(); it++)
    {
        cout << *it << endl;
    }
}

输出如下：

Intersection:
a
b
c
Difference:
d
e
Union:
a
b
c
d
e
x
y