#include <iostream>
#include <vector>
int main() {
    std::vector<int> vector{1,2,3,4,5,6,7,8,9};
    std::cout << "vectoor: ";
    for(auto el : vector) {
        std::cout << el << " ";
    //截取前4个数
    std::vector<int>::const_iterator first1 = vector.begin();
    std::vector<int>::const_iterator last1  = vector.begin() + 4;
    std::vector<int> cut1_vector(first1, last1);
    std::cout << "\ncut1_vector: ";
    for(auto el : cut1_vector) {
        std::cout << el << " ";
    //截取后4个数
    std::vector<int>::const_iterator first2 = vector.end() - 4;
    std::vector<int>::const_iterator last2  = vector.end();
    std::vector<int> cut2_vector(first2, last2);
    std::cout << "\ncut2_vector: ";
    for(auto el : cut2_vector) {
        std::cout << el << " ";
    std::cout << "\n";