c++ vector点集取交集

以下是两种C++ vector点集取交集的例子：

引用：使用multiset实现

#include <iostream>
#include <vector>
#include <set>
#include <algorithm>

using namespace std;

int main() {
    int iarr1[] = {1, 2, 3, 3, 4, 5, 6, 7, 9};
    int iarr2[] = {1, 4, 3, 9, 10};
    multiset<int> iset1(begin(iarr1), end(iarr1));
    multiset<int> iset2(begin(iarr2), end(iarr2));
    vector<int> ivec(20);
    auto iter = set_intersection(iset1.begin(), iset1.end(), iset2.begin(), iset2.end(), ivec.begin());
    ivec.resize(iter - ivec.begin());
    for (auto i : ivec) {
        cout << i << " ";
    }
    return 0;
}

引用：使用sort实现

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int iarr1[] = {1, 2, 3, 3, 6, 7, 4, 5};
    int iarr2[] = {1, 4, 3, 10, 9};
    sort(begin(iarr1), end(iarr1));
    sort(begin(iarr2), end(iarr2));
    vector<int> ivec(10);
    auto iter = set_intersection(begin(iarr1), end(iarr1), begin(iarr2), end(iarr2), ivec.begin());
    ivec.resize(iter - ivec.begin());
    for (auto i : ivec) {
        cout << i << " ";
    }
    return 0;
}