Dijkstra

import java.util.Stack;

public class Dijkstra {//最短路径算法
    public static void main(String[] args) {
        Stack<Integer> stacknum=new Stack<Integer>();
        Stack<Character> stacksin=new Stack<Character>();
        String  a= "((1+(2+3))*2)";
        char []std=a.toCharArray();
        for(int i=0;i<std.length;i++){
            if(std[i]=='(') ;
            else if(std[i]=='+')
                stacksin.push(std[i]);
            else if(std[i]=='*')
                stacksin.push(std[i]);
            else if(std[i]==')'){//右括号开始计算的标志
                char c=stacksin.pop();
                int number=stacknum.pop();
                if(c=='+'){
                    number=number+stacknum.pop();
                }else if(c=='*'){
                    number =number*stacknum.pop();
                }
                stacknum.push(number);
            }else{
                stacknum.push(Integer.parseInt(Character.toString(std[i])));//将可分析的字符串转化为整数
            }
        }
        System.out.println(stacknum.pop());
    }
}