import java.util.Stack;public class Solution { Stack<Integer> dataStack = new Stack(); Stack<Integer> minStack = new Stack(); public void push(int node) { dataStack.push(node); if (minStack.size()==0||minStack.peek()>node){ minStack.push(node); }else { minStack.push(minStack.peek()); } } public void pop() { dataStack.pop(); minStack.pop(); } public int top() { return dataStack.peek(); } public int min() { return minStack.peek(); }}