1、set_intersection 求两个集合的交集
2、set_union 求两个容器的并集
3、set_difference 求两个集合的差集
4、两集合必须是有序序列
5、返回结果最后一个元素的迭代器位置
6、头文件 #include<algorithm>
7、测试程序
#include"pch.h"
#include<iostream>
#include<vector>
#include<algorithm>
#include<iterator>
using namespace std;
//set_intersection 求两个集合的交集
//两集合必须是有序序列
//返回交集的最后一个元素的迭代器位置
void test01()
{
vector<int>v1;
vector<int>v2;
for (int i = 0; i <10; i++)
{
v1.push_back(i);
v2.push_back(i);
}
cout << "v1: ";
copy(v1.begin(), v1.end(), ostream_iterator<int>(cout, " "));
cout << endl;
cout << "v2: ";
copy(v2.begin(), v2.end(), ostream_iterator<int>(cout, " "));
cout << endl;
vector<int>vTarget;
vTarget.resize(min(v1.size(), v2.size()));//两个容器中取小的开辟size
//求交集
vector<int>::iterator itEnd = set_intersection(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
cout << "v1 与 v2 的交集: ";
copy(vTarget.begin(), itEnd, ostream_iterator<int>(cout, " "));
cout << endl;
}
//set_union 求两个容器的并集
void test02()
{
vector<int>v1;
vector<int>v2;
for (int i = 0; i < 10; i++)
{
v1.push_back(i);
v2.push_back(i+5);
}
cout << "v1: ";
copy(v1.begin(), v1.end(), ostream_iterator<int>(cout, " "));
cout << endl;
cout << "v2: ";
copy(v2.begin(), v2.end(), ostream_iterator<int>(cout, " "));
cout << endl;
vector<int>vTarget;
vTarget.resize(v1.size() + v2.size());//两容器元素完全不同时开辟size
//求并集
vector<int>::iterator itEnd = set_union(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
cout << "v1 与 v2 的并集: ";
copy(vTarget.begin(), itEnd, ostream_iterator<int>(cout, " "));
cout << endl;
}
//set_difference 求两个集合的差集
//集合必须为有序序列
//返回目标容器最后一个元素的迭代器地址
void test03()
{
vector<int>v1;
vector<int>v2;
for (int i = 0; i < 10; i++)
{
v1.push_back(i);
v2.push_back(i + 5);
}
cout << "v1: ";
copy(v1.begin(), v1.end(), ostream_iterator<int>(cout, " "));
cout << endl;
cout << "v2: ";
copy(v2.begin(), v2.end(), ostream_iterator<int>(cout, " "));
cout << endl;
vector<int>vTarget;
vTarget.resize(max(v1.size(), v2.size()));//差集最多为两个集合最大的
//求差集
vector<int>::iterator itEnd = set_difference(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
cout << "v1 与 v2 的差集: ";
copy(vTarget.begin(), itEnd, ostream_iterator<int>(cout, " "));
cout << endl;
vector<int>::iterator itEnd1 = set_difference( v2.begin(), v2.end(),v1.begin(), v1.end(), vTarget.begin());
cout << "v2 与 v1 的差集: ";
copy(vTarget.begin(), itEnd1, ostream_iterator<int>(cout, " "));
cout << endl;
}
int main()
{
/*test01();*/
//test02();
test03();
}