得到栈中的最小值

#include <iostream>
#include <stack>
using namespace std;

class GetMinStack{
public:
    void push(int x);

    void pop();

    int top();

    int getmin();
private:
    stack<int> S;
    stack<int> temp;
};

void GetMinStack::push(int x)
{
    if(S.empty())
    {
        temp.push(x);
        S.push(x);
    }
    else
    {
        if(x < temp.top())
        {
            temp.push(x);
            S.push(x);
        }
        else
        {
            temp.push(temp.top());
            S.push(x);
        }
    }
}
void GetMinStack::pop()
{
    S.pop();
    temp.pop();
}
int GetMinStack::top()
{
    return S.top();
}
int GetMinStack::getmin()
{
    return temp.top();
}

int main()
{
    GetMinStack TestStack;
    TestStack.push(-2);
    cout << TestStack.top() << endl;
    cout << TestStack.getmin() << endl;
    TestStack.push(0);
    cout << TestStack.getmin() << endl;
    TestStack.push(-6);
    cout << TestStack.getmin() << endl;
    TestStack.pop();
    cout << TestStack.getmin() << endl;
    return 0;
}