1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

Stack<Integer> stackData1 = new Stack<Integer>();
    Stack<Integer> stackData2 = new Stack<Integer>();


    public void push(int node) {
        stackData1.push(node);
        if(stackData2.isEmpty()||node<=min()){
            stackData2.push(node);
        }
    }
    
    public void pop() {
        if(stackData1.peek().equals(min())){
            stackData2.pop();
        }
        stackData1.pop();
    }
    
    public int top() {
        return stackData1.peek();
    }
    
    public int min() {
        return stackData2.peek();
    }