编写程序，输入两个集合setA和setB，分别输出它们的交集、并集和差集setA-setB。

好的，我可以回答这个问题。以下是程序的代码：

#include <iostream>
#include <set>

using namespace std;

int main() {
    set<int> setA, setB;
    int num;

    // 输入集合A
    cout << "请输入集合A的元素个数：";
    cin >> num;
    cout << "请输入集合A的元素：";
    for (int i = ; i < num; i++) {
        int elem;
        cin >> elem;
        setA.insert(elem);
    }

    // 输入集合B
    cout << "请输入集合B的元素个数：";
    cin >> num;
    cout << "请输入集合B的元素：";
    for (int i = ; i < num; i++) {
        int elem;
        cin >> elem;
        setB.insert(elem);
    }

    // 输出交集
    cout << "集合A和集合B的交集为：";
    set<int> intersection;
    set_intersection(setA.begin(), setA.end(), setB.begin(), setB.end(), inserter(intersection, intersection.begin()));
    for (auto elem : intersection) {
        cout << elem << " ";
    }
    cout << endl;

    // 输出并集
    cout << "集合A和集合B的并集为：";
    set<int> unionSet;
    set_union(setA.begin(), setA.end(), setB.begin(), setB.end(), inserter(unionSet, unionSet.begin()));
    for (auto elem : unionSet) {
        cout << elem << " ";
    }
    cout << endl;

    // 输出差集
    cout << "集合A和集合B的差集为：";
    set<int> difference;
    set_difference(setA.begin(), setA.end(), setB.begin(), setB.end(), inserter(difference, difference.begin()));
    for (auto elem : difference) {
        cout << elem << " ";
    }
    cout << endl;

    return ;
}