源程序如下，能幫我找下錯誤嗎#include<iostream>#include<vector>using namespace std;class A{public:int a;A(int aa){a=aa;}void print(){cout<<a<<endl;}};int main(){vector<A> v;vector<A>::iterator p=v.begin();A aaa(4);A bb(6);v.push_back(aaa);v.push_back(aaa);v.push_back(aaa);v.push_back(aaa);p++;p++;v.insert(p,bb);for(int i=0;i<5;i++)v[i].print();}能加上vector的各個函數用法的詳細解釋的話更好，感激不盡！