MinStack.cpp

stack<int> s;
stack<int> mins;

MinStack::MinStack() {
   
    
     while(!s.empty()){
        s.pop();
    }
    while(!mins.empty()){
        mins.pop();
    }
}

void MinStack::push(int x) {
    s.push(x);
if(mins.size()==0)
mins.push(x);
else
{
    if(x<mins.top())
    mins.push(x);
    else
    mins.push(mins.top());
}
}


void MinStack::pop() {
    if(s.size()!=0)
    {
    s.pop(); 
    mins.pop();
    }
}

int MinStack::top() {
    if(s.size()==0)
    return -1;
    return s.top();
}

int MinStack::getMin() {
    if(mins.size()==0)
    return -1;
    return mins.top();
}