COMP-200: Intro to Computer Systems

Assignment 4

mo khan - 3431709

Choose ONE exercise each from Chapters 10, 11, and 12. There are no chapter end exercises for Chapter 9.

Chapter 10:

9. In Python, indentation is used to indicate the extent of a block of code. What is the output of the following Python code?

!include assignments/4/main.py

$ python assignments/4/main.py
second is bigger
first is bigger

Chapter 11:

1. Identify the tokens in each of the following statements. (You do not need to classify them; just identify them.) a. if (a == b1) a = x + y;

   token	type
   if	if condition
   (	left paren
   a	symbol
   ==	comparison operator
   b1	symbol
   a	symbol
   =	assignment operator
   x	symbol
   +	addition operator
   y	symbol
   ;	statement terminator

   b. delta = epsilon + 1.23 - sqrt(zz);

   token	type
   delta	symbol
   =	assignment operator
   epsilon	symbol
   +	addition operator
   1.23	floating point number
   -	subtraction operator
   sqrt	symbol
   (	left paren
   zz	symbol
   )	right paren
   ;	statement terminator

   c. print(Q);

   token	type
   print	symbol
   (	left paren
   Q	symbol
   )	right paren
   ;	statement terminator

Chapter 12:

5. Given the Turing machine instruction (1,1,0,2,L) and the configuration ...b 1 0 b... draw the next configuration.

• (1,1,0,2,L) - Move left once and halt the machine

--------|*|----------
|.|.|.|b|1|0|b|.|.|.|
--------|*|----------
         ^
         |- 1

------|*|------------
|.|.|.|b|0|0|b|.|.|.|
------|*|------------
       ^
       |- 2