表达式求值

import java.util.Scanner;

public class jklj {
//假定无括号
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		String str=sc.nextLine();
		Stack ds ;//数据栈
		FStack fs;//符号栈
		while(n--!=0)
		{
			str = sc.nextLine();
			ds = new Stack();
			fs = new FStack();
			char[] ch = str.toCharArray();
			int l = 0 ;
			/*
			 * 如果是符号  把其之前的数字提取
			 * 存入数据栈中
			 * 然后判断当前符号和符号栈中的符号优先级，再决定是否取出数据进行运算
			 */
			for(int i = 0 ; i<ch.length;i++)
			{
				if(Type(ch[i]))//如果是符号
				{
					int count = 1;
					int f =0;
					int t = i-1;
					while(t>=l)
					{
						f+= (ch[t]-'0')*count;
						count *= 10;
						t--;
					}
					l=i+1;
					ds.push(f);//数据入栈
					//判断是否要进行运算
					//考虑    数据栈的数是够用的
					while(!fs.isEmpty()&&Judge(fs.peek(),ch[i]) )
					{
						int b = ds.pop();
						int a = ds.pop();
						char ppp = fs.pop();
						switch(ppp)
						{
							case '+':ds.push(a+b);break;
							case '-':ds.push(a-b);break;
							case '*':ds.push(a*b);break;
							case '/':ds.push(a/b);break;
						}
					}
					fs.push(ch[i]);
				}
			}
			int count = 1;
			int f =0;
			int t = ch.length-1;
			while(t>=l)
			{
				f+= (ch[t]-'0')*count;
				count *= 10;
				t--;
			}
			ds.push(f);//数据入栈
			while(!fs.isEmpty())
			{
				int b = ds.pop();
				int a = ds.pop();
				char ppp = fs.pop();
				switch(ppp)
				{
					case '+':ds.push(a+b);break;
					case '-':ds.push(a-b);break;
					case '*':ds.push(a*b);break;
					case '/':ds.push(a/b);break;
				}
			}
			System.out.println(ds.peek());
		}
	}
//判断是否要进行运算
	private static boolean Judge(char peek, char c) 
	{
		int a = F(peek);
		int b = F(c);
		if(b<=a)
			return true;
		return false;
	}
	private static int F(char peek) 
	{
		if(peek == '*'||peek =='/')
			return 1;
		return 0;
	}
	private static boolean Type(char c) 
	{
		if(c =='+'||c =='-'||c =='*'||c =='/')
			return true;
		return false;
	}
}

//数据栈
class Stack
{
	int top ;
	int data[];
	public Stack()
	{
		data = new int [100];
		top = -1;
	}
	public void push(int item)
	{
		data[++top] = item;
	}
	
	public int pop()
	{
		return data[top--];
	}
	public boolean isEmpty() {
		if(top == -1)
			return true;
		return false;
	}
	public int peek()
	{
		return data[top];
	}
}

//符号栈
class FStack
{
	int top ;
	char data[];
	public FStack()
	{
		data = new char [100];
		top = -1;
	}
	public void push(char item)
	{
		data[++top] = item;
	}
	
	public char pop()
	{
		return data[top--];
	}
	public boolean isEmpty() {
		if(top == -1)
			return true;
		return false;
	}
	public char peek()
	{
		return data[top];
	}
}