题解 | #包含min函数的栈#

使用一个辅助栈记录当前最小值

public class Solution {
    Stack<Integer> stack1 = new Stack(),stack2 = new Stack();
    
    public void push(int node) {
        stack1.push(node);
        if(stack2.isEmpty()){
            stack2.push(node);
        }else{
            if(stack2.peek() > node){
                stack2.push(node);
            }else{
                stack2.push(stack2.peek());
            }
        }
    }
    
    public void pop() {
        stack1.pop();
        stack2.pop();
    }
    
    public int top() {
        return stack1.peek();
    }
    
    public int min() {
        return stack2.peek();
    }
}