标签：str tar struct removes remove ant pop new array
题目：
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
链接： http://leetcode.com/problems/min-stack/
2/18/2017, Java
注意！我们其实可以直接用stack不用ArrayList的！
Integer 和int是不相等的，第14行如果是Integer x = ...那么15行永远不相等！
1 public class MinStack { 2 ArrayList<Integer> list = new ArrayList<Integer>(); 3 ArrayList<Integer> min = new ArrayList<Integer>(); 4 5 /** initialize your data structure here. */ 6 public MinStack() {} 7 8 public void push(int x) { 9 list.add(x); 10 if (min.size() == 0 || x <= min.get(min.size() - 1)) min.add(x); 11 } 12 13 public void pop() { 14 int x = list.remove(list.size() - 1); 15 if (x == min.get(min.size() - 1)) min.remove(min.size() - 1); 16 } 17 18 public int top() { 19 return list.get(list.size() - 1); 20 } 21 22 public int getMin() { 23 return min.get(min.size() - 1); 24 } 25 }
标签：str tar struct removes remove ant pop new array
原文地址：http://www.cnblogs.com/panini/p/6414720.html
