中缀表达式转换到后缀表达式（java实现）

/*
将中缀表达式转换为后缀表达式
定义优先级：'(' :4
'*',  '/' :3
'+', '-': 2
')'      : 1
思路：
循环遍历输入字符数组
if input[i]是数字，则print; continue;
循环
if栈空，则input[i]入栈,break;
if outputPriority < inputPriority ,则input[i]入栈，break;
if outputPriority >= inputPriority 
if output != '(' ,则print(output),continue;
else
if(input != ')'),则出栈; break;
else input[i] 入栈; break;
*/

import java.util.*;public class MidExpToLaterExp{public static void main(String[] args){Scanner scan = new Scanner(System.in);char[] input = scan.next().toCharArray();Stack stack = new Stack(10);for(int i = 0; i < input.length; i ++){int inputPriority = getPriority(input[i]);if(inputPriority == 0){System.out.print(input[i]);continue;}while(true){if(stack.isEmpty()){stack.push(input[i]);break;}char output = stack.peek();int outputPriority = getPriority(output);if(outputPriority < inputPriority){stack.push(input[i]);break;}else{if(output != '('){stack.pop();System.out.print(output);continue;}else{if(input[i] != ')'){stack.push(input[i]);break;}else{stack.pop();break;}}}}}while(!stack.isEmpty()){System.out.print(stack.pop());}}public static int getPriority(char ch){int priority = 0;switch(ch){case '(' : priority = 4; break;case '*' : case '/' : priority = 3; break;case '+' : case '-' : priority = 2; break;case ')' : priority = 1; break;}return priority;}}class Stack{private char[] array;private int top;private int maxSize;public Stack(int maxSize){this.maxSize = maxSize;array = new char[maxSize];top = 0;}public void push(char ch){array[top++] = ch;}public char pop(){return array[--top];}public char peek(){return array[top -1];}public boolean isEmpty(){return top == 0;}public boolean isFull(){return top == maxSize;}}