实现对vector的截段操作

实现对vector的截段操作。

C++版本

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