包含min函数的栈
题目:定义栈的数据结构,请在该类型中实现一个能够得到栈最小元素的min函数。
思路:可以用一个变量来保存当前最小的数,但是这样在最小的数出栈之后剩余数的最小数怎么获取?这就需要使用一个同样大小的辅助栈,辅助栈保存当前最小的数,这样就能实现题目所要求的min函数。
实现代码:
import java.util.Stack; public class Solution { public Stack<Integer> mainStack; public Stack<Integer> minStack; public Solution() { mainStack = new Stack<Integer>(); minStack = new Stack<Integer>(); } public void push(int node) { mainStack.push(node); if(minStack.isEmpty()) { minStack.push(node); } else { int cur = minStack.peek(); if(node < cur) minStack.push(node); else minStack.push(cur); } } public void pop() { if(!mainStack.isEmpty()) { mainStack.pop(); minStack.pop(); } } public int top() { if(!mainStack.isEmpty()) return mainStack.peek(); else return 0; } public int min() { if(!minStack.isEmpty()) return minStack.peek(); else return 0; } }
作者:Pickle
声明:对于转载分享我是没有意见的,出于对博客园社区和作者的尊重一定要保留原文地址哈。
致读者:坚持写博客不容易,写高质量博客更难,我也在不断的学习和进步,希望和所有同路人一道用技术来改变生活。觉得有点用就点个赞哈。
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