![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
有如下程序: #include <iostream> using namespace std; class Stack { public: Stack(unsigned n= 10):size(n) {rep_=ew int[size]; top=0;} Stack(Stack& s):size(s.size) { rep_=new int[size]; for(int i=0;i<size;i++) rep_[i]=s.rep_[i]; top=s.top; } ~Stack() {delete[]rep_;} void push(int a) {rep_[top]=a; top++;} int pop() {--top;return rep_[top];} bool isEmpty() const {return top==0;} private: int *rep_; unsigned size,top; }; int main() { Stack s1; for(int i= 1;i<5 ;i++) s1. push(i); Stack s2(s1); for(i= 1 ;i<3;i++) cout<<s2.pop()<<','; s2.push(6); si.push(7); while(!s2.isEmpty()) cout<<s2.pop()<<','; return 0; }执行上面程序的输出是______ 。