4/27打卡 stl初识vector

#include <iostream>
#include <vector>
using namespace std;


void test()
{
    vector<vector<int>>v;
    vector<int> v1;
    vector<int> v2;
    vector<int> v3;
    vector<int> v4;
    for (int i = 0; i < 4; i++)
    {
        v1.push_back(i + 1);
        v2.push_back(i + 2);
        v3.push_back(i + 3);
        v4.push_back(i + 4);
    }
    v.push_back(v1);
    v.push_back(v2);
    v.push_back(v3);
    v.push_back(v4);
    for (vector<vector<int>>::iterator it = v.begin(); it != v.end(); it++)
    {
        for (vector<int>::iterator vit = (*it).begin(); vit != (*it).end(); vit++)
        {
            cout << *vit << " ";
        }
        cout << endl;
    }
}

int main() {
    test();
    return 0;
}