Assignment 3

1. Explain why the following if statement results in syntax error in C, Java, and C#?

   
      if (x==1) y = 2 else y = 3;
   

   
   
2. Give a CFG for each of the following languages.
   • Strings of 0's and 1's with an equal number of 0's and 1's.
   • Strings of 0's and 1's with an unequal number of 0's and 1's.
   
   
3. Give a context-free grammar for each of the following languages over S={a,b}:

    

   a) {aⁱb^j  | i,j≥0}
   
   

   b) {aⁱb^ja^k | i+j=k,k>=0}
   
   

4. Show the parse tree of the following Java program:

   
   import java.util.Scanner;
   
   class Ex {
   	public static void main(String[] args){
   		Scanner keyboard = new Scanner(System.in);
   		System.out.println("enter a number");
   		double x  = keyboard.nextDouble();
   		System.out.println("x^2+2x+1 = " + x*x+2*x+1);
   	}
   }