vector删除中间某一元素

int main()
{
    vector<int> a(10);
    int count = 0;
    cout << a.size() << endl;
    cout << a.capacity() << endl;
    
    for (auto &i : a)
    {
        i = count;
        count++;
    }
    auto it = a.begin()+5;
    a.erase(it);
    a.erase(a.begin(), a.begin() + 1);
    cout << a.size() << endl;
    cout << a.capacity() << endl;
    return 0;
}

size变小

capacity没有变化