1. [20 marks] Write a program that takes a string and prints it out such that each letter of the string is printed out onto the standard output as a banner. 
The program may take three arguments -m (number of columns, default 6), -n (number of rows, default 6), -c (the display character, default #).

Sample execution:

java Display -m 6 -n 6 -c x dee

xxxxx  xxxxxx xxxxxx 
x    x x      x      
x    x xxxxx  xxxxx  
x    x x      x      
x    x x      x      
xxxxx  xxxxxx xxxxxx 

// Instructions:
// Main file name: Display.java
// Assume that you will be asked to print strings containing letters
[aeioubcdef] only.

2. [20 marks] Stack machine.
Write a Java code to interpret instructions for a simple stack machine.

The different supported instructions are:
push - pushes the following integer on to the stack.
pop - pops the top element off the stack and prints it. 
dup - duplicates the top element of the stack and pushes it back on to the stack. 
add - pops off the top two elements off the stack, adds them and pushes the result back onto the stack.
sub - pops off the top two elements off the stack, subtracts them (stack[0] - stack[1]) and pushes the result back onto the stack.
mul - pops off the top two elements off the stack, multiplies them and pushes the result back onto the stack.
div - pops off the top two elements off the stack, divides them (integer divison, stack[0]/stack[1]) and pushes the result back onto the stack.

// Corner case:
For each of the operations that pop elements from the stack, if the stack is empty, the operation becomes a nop.

Assume that you will be given a class named Code.java that contains the
sequence of stack machine instructions (sample file given below) 

Your main file name should be called the Calc.java; in which you will write the appropriate Java instructions to interpret the stack machine instructions given in Code.java.

Example Code.java:

public final class Code{

public static final String []code = new String[] {
	"push",
	"3",
	"push",
	"2",
	"dup",
	"pop",
	"sub",
	"pop"
	};

}

Expected output for this Code:
2
-1

===============
Submission guidelines:

Your submissions should be a single .tar.gz file of the form <yourroll>.tar.gz.
Unzipping it must produce a single directory matching your roll number e.g., CS20B001.
This directory must have a single subdirectory: A0 and file checklist.txt [see moodle for the details on Checklist.txt]
A0 must have two sub-directories: Q1 and Q2.
All the files related to the first question must be in Q1 and those related to the second question in Q2.

The following sample commands should be able to compile and run the respective submissions:

In the Q1 directory:
javac Display.java
java Display -m 6 -n 6 -c x dew


In the Q2 directory:
cp /tmp/Code.java . # To copy my version of Code.java
javac Calc.java
java Calc

Your code should print nothing other than the relevant output stated in this document. No debug messages etc should be printed out.