一、实现一个特殊的栈，在实现栈的基本功能的基础上，再实现返回栈中最小元素的操作

请指教交流！

package com.it.hxs.c01;

import java.util.Stack;

/*
 实现一个特殊的栈，在实现栈的基本功能的基础上，再实现返回栈中最小元素的操作
 */
public class GetMinStack {

    public static void main(String args[]) {
        GetMinStack demoStack = new GetMinStack();
        demoStack.push("1");
        demoStack.push("2");
        demoStack.push("");
        System.out.println(demoStack.getMin());
        System.out.println(demoStack.pop());
        System.out.println(demoStack.getMin());
    }

    private Stack<String> stringStack;
    private Stack<Integer> intStack;
    private Stack<String> minStack;

    public GetMinStack() {
        this.stringStack = new Stack<String>();
        this.intStack = new Stack<Integer>();
        this.minStack = new Stack<String>();
    }

    public void push(String content) {
        if ("".equals(content)||content == null) {
            throw new RuntimeException("添加的元素值不能为空！");
        } else {
            int data = string2ASCII(content);
            stringStack.push(content);
            if (!intStack.isEmpty()) {
                int curIntStackData = intStack.peek();
                if (curIntStackData >= data) {// 数值栈intStack中最上面元素大于当前推入元素，则当前元素为最小，则当前元素推入最小元素栈minStack
                    minStack.push(content);
                } else {
                    minStack.push(minStack.peek());
                }
            } else {
                minStack.push(content);
            }
            intStack.push(data);
        }
    }

    public String pop() {
        String result = "无元素";
        if (!intStack.isEmpty()) {
            intStack.pop();
        }
        if (!minStack.isEmpty()) {
            minStack.pop();
        }
        if (!stringStack.isEmpty()) {
            result = stringStack.pop();
        }
        return result;
    }

    public String getMin() {
        String result = "无元素";
        if (!minStack.isEmpty()) {
            result = minStack.peek();
        }
        return result;
    }

    // 字符串转ASCII
    public static int string2ASCII(String content) {
        int result = 0;
        char[] chars = content.toCharArray();
        for (char c : chars) {
            int temp = (int) c;
            result = result + temp;
        }
        return result;
    }

}