[C/C++标准库]_[初级]_[集合操作]

set_difference

set_union

set_symmetric_difference

#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <vector>
#include <iostream>
#include <string>

using namespace std;

//1.可重复值
//2.集合对称差
void ExampleSetSymmetricDifference()
{
vector<int> i1;
vector<int> i2;

//    int i1[] = {1,2,5,7};
//	int i2[] = {0,1,2,3};
//	int i2[] = {0,1,2,3,4,5,6,7};
std::vector<int>::iterator it;
i1.push_back(1);
i1.push_back(2);
i1.push_back(5);
i1.push_back(8);

i2.push_back(0);
i2.push_back(1);
i2.push_back(2);
i2.push_back(3);
i2.push_back(4);
i2.push_back(5);
i2.push_back(6);
i2.push_back(6);
i2.push_back(7);

sort(i1.begin(),i1.end());
sort(i2.begin(),i2.end());

vector<int> res(i2.size()+i1.size());
//对称差
it = set_symmetric_difference(i1.begin(),i1.end(),i2.begin(),i2.end(),res.begin());

res.resize(it-res.begin());
size_t size = res.size();

printf("size %d\n",size);
for (it=res.begin(); it!=res.end(); ++it)
{
std::cout << ' ' << *it;
}
std::cout << std::endl;
}

//1.可重复值
//2.集合差集
void ExampleSetDifference()
{
int first[] = {5,10,15,15,25};
int second[] = {50,40,30,20,10};
std::vector<int> v(10);                      // 0  0  0  0  0  0  0  0  0  0
std::vector<int>::iterator it;

std::sort (first,first+5);     //  5 10 15 20 25
std::sort (second,second+5);   // 10 20 30 40 50

//frist相对second的不同值
it=std::set_difference (first, first+5, second, second+5, v.begin());
//  5 15 25  0  0  0  0  0  0  0
v.resize(it-v.begin());                      //  5 15 25

std::cout << "The difference has " << (v.size()) << " elements:\n";
for (it=v.begin(); it!=v.end(); ++it)
{
std::cout << ' ' << *it;
}
std::cout << std::endl;
}

//1.可重复值
//1.集合并集,共有的只出现一次
void ExampleSetUnion()
{
int first[] = {5,10,15,15,25};
int second[] = {50,40,30,20,10};
std::vector<int> v(10);                      // 0  0  0  0  0  0  0  0  0  0
std::vector<int>::iterator it;

std::sort (first,first+5);     //  5 10 15 20 25
std::sort (second,second+5);   // 10 20 30 40 50

it=std::set_union (first, first+5, second, second+5, v.begin());

v.resize(it-v.begin());
std::cout << "The union has " << (v.size()) << " elements:\n";
for (it=v.begin(); it!=v.end(); ++it)
{
std::cout << ' ' << *it;
}
std::cout << std::endl;
}

int main(int argc, char *argv[])
{
std::cout << "SetDifference" << endl;
ExampleSetDifference();

std::cout << "SetSymmetricDifference" << endl;
ExampleSetSymmetricDifference();

std::cout << "SetUnion" << endl;
ExampleSetUnion();
return 0;
}

SetDifference
The difference has 4 elements:
5 15 15 25
SetSymmetricDifference
size 7
0 3 4 6 6 7 8
SetUnion
The union has 9 elements:
5 10 15 15 20 25 30 40 50
[Finished in 0.3s]