#include <iostream>
#include <vector>

using namespace std;

int main() {
    // 创建vector，用于存储整型数据
    vector<int> vec;
    int i;

    // 显示vec初始大小
    cout << "Vector size = " << vec.size() << endl;

    // 追加整数
    for (int i = 0; i < 5; i++){
        vec.push_back(i);
    }
    cout << "Vector size = " << vec.size() << endl;

    return 0;
}

Vector size = 0
Vector size = 5
请按任意键继续. . .