剑指offer——包含min函数的栈

 1 import java.util.Stack;
 2  
 3 public class Solution {
 4     private static Stack<Integer> mStack=new Stack<Integer>();
 5     private static Stack<Integer> minStack=new Stack<Integer>();
 6   
 7     public void push(int node) {
 8         if(minStack.size()==0 || node<minStack.peek()){
 9             minStack.push(node);
10         }else{
11             minStack.push(minStack.peek());
12         }
13         mStack.push(node); 
14     }
15      
16     public void pop() {
17         if(!mStack.isEmpty()){
18             mStack.pop();
19             minStack.pop();
20         }
21          
22     }
23      
24     public int top() {
25         return mStack.peek();
26          
27     }
28      
29     public int min() {
30         return minStack.peek();
31     }
32 }