1112. Lazy Math Instructor

单点时限: 2.0 sec

内存限制: 256 MB

A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question asked. Students may write correct answers in different forms which makes grading very hard. So, the instructor needs help from computer programmers and you can help.

You are to write a program to read different formulas and determine whether or not they are arithmetically equivalent.

输入格式

The first line of the input contains an integer N (1 <= N <= 20) that is the number of test cases. Following the first line, there are two lines for each test case. A test case consists of two arithmetic expressions, each on a separate line with at most 80 characters. There is no blank line in the input. An expression contains one or more of the following:

Single letter variables (case insensitive).

Single digit numbers.

Matched left and right parentheses.

Binary operators +, - and * which are used for addition, subtraction and multiplication respectively.

Arbitrary number of blank or tab characters between above tokens.

Note: Expressions are syntactically correct and evaluated from left to right with equal precedence (priority) for all operators. The coefficients and exponents of the variables are guaranteed to fit in 16-bit integers.

输出格式

Your program must produce one line for each test case. If input expressions for each test data are arithmetically equivalent, “YES”, otherwise “NO” must be printed as the output of the program. Output should be all in upper-case characters.

样例

Input
3
(a+b-c)*2
(a+a)+(b*2)-(3*c)+c
a*2-(a+c)+((a+c+e)*2)
3*a+c+(2*e)
(a-b)*(a-b)
(a*a)-(2*a*b)-(b*b)
Output
YES
YES
NO

4 人解决,10 人已尝试。

4 份提交通过,共有 16 份提交。

8.4 EMB 奖励。

创建: 17 年,3 月前.

修改: 7 年,2 月前.

最后提交: 1 年,4 月前.

来源: Tehran 2000

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