常用集合算法

交集

• iterator.end set_intersection(iterator beg, iterator end, iterator beg2, iterator end2, iterator dest); 并集
• iterator.end set_union(iterator beg, iterator end, iterator beg2, iterator end2, iterator dest); 差集
• iterator.end set_difference(iterator beg, iterator end, iterator beg2, iterator end2, iterator dest);

title:Important
数学问题常用算法

#include <vector>
#include <>
#include <iostream>
using namespace std;
 
void print(vector<int>& v)
{
    for(vector<int>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;
}
 
int main()
{
    vector<int>v1;
    vector<int>v2;
    vector<int>v3;
    vector<int>v4;
    vector<int>v5;
    
    for(int i = 0; i < 10; i++)
    {
        v1.push_back(i);
        v2.push_back(i + 5);
    }
    print(v1);
    print(v2);
    //目标容器需要提前开辟空间
    v3.resize(5);
    set_intersection(v1.begin(), v1.end(), v2.begin(), v2.end(), v3.begin());
    print(v3);
    
    v3.resize(15);
    set_union(v1.begin(), v1.end(), v2.begin(), v2.end(), v3.begin());
    print(v4);
    
    v3.resize(10);
    set_difference(v1.begin(), v1.end(), v2.begin(), v2.end(), v3.begin());
    print(v5);
    return 0;
}
/*output:
0 1 2 3 4 5 6 7 8 9
5 6 7 8 9 10 11 12 13 14
5 6 7 8 9
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
0 1 2 3 4 10 11 12 13 14
 
*/