题解 | #包含min函数的栈#

import java.util.*;
import java.util.Stack;

public class Solution {

    Stack<Integer> stackVal = new Stack<Integer>();
    //本地难点：node和min操作同步记录
    Stack<Integer> stackMin = new Stack<Integer>();

    public void push(int node) {
        stackVal.add(node);
        if (stackMin.isEmpty()) {
            stackMin.push(node);
        } else {
            if (node < stackMin.peek()) {
                stackMin.push(node);
            } else {
                stackMin.push(stackMin.peek());
            }
        }
    }

    public void pop() {
        stackVal.pop();
        stackMin.pop();
    }

    public int top() {
        return stackVal.peek();
    }

    public int min() {
        return stackMin.peek();
    }
}