队列和栈面试题（一）— 请编写一个程序，按升序对栈进行排序，要求最多只能使用一个额外的栈存放临时数据

#include<iostream>
#include<string>
#include<stack>//pop,top,push
#include<vector>
using namespace std;
class TwoStacks {
public:
    vector<int> twoStacksSort(vector<int> numbers) 
    {
        stack<int> sta;
        for(vector<int>::reverse_iterator riter=numbers.rbegin();riter!=numbers.rend();riter++)
            sta.push(*riter);
        StackSort(sta);
        vector<int> res;
        while(!sta.empty())
        {
            res.push_back(sta.top());
            sta.pop();
        }
        return res;
    }
    void StackSort(stack<int> &sta)
    {
        stack<int> help;
        while(!sta.empty())
        {
            int res=sta.top();
            sta.pop();
            if(help.empty()||res<=help.top())
                help.push(res);
            else
            {
                while(!help.empty()&&res>help.top())
                {
                    sta.push(help.top());
                    help.pop();
                }
                help.push(res);
            }
        }
        while(!help.empty())
        {
            sta.push(help.top());
            help.pop();
        }
    }
};
int main()
{
    int a[5]={1,2,3,4,5};
    TwoStacks A;
    vector<int> arr(a,a+5),res;
    res=A.twoStacksSort(arr);
    for(vector<int>::iterator iter=res.begin();iter!=res.end();iter++)
        cout<<*iter<<" ";
    return 0;
}