Homework 1              ENEE 114                Spring 2007

	POSTED: Friday February 9
        DUE: 11:59 pm Monday February 19

*       name your answers as hw1.1.c, hw1.2.c, ..., and submit
        each of them via the GLUE submit command
*       make sure that you document each hw1.x.c file

/****************************************************************************/

1. Write down the UNIX commands to generate the following directory
	structure under your GLUE root directory. (You are highly
	recommended to do so too).
   For example, Proj1 is a subdirectory under Project, which is in turn
	a subdirectory of ENEE114, which is a subdirectory under your root
   This homework is posted at /dept/enee/public_html/class/enee114/homework
	with file name hw1.txt. Give the command that copies it to the HW1
	subdirectory, assuming that you are now in the root directory.

   -root
     -ENEE114
	-Project
	   -Proj1
	   -Proj2
	-Homework
	   -HW1
	-Quizzes
	-Recitation
	-Notes

2. Give the output of the following while loop: 

 	int i = 1;
 	while ( i < 10 )
	{ printf("i = %d\n", i);
   	  i = i + 2;
	}

   what will be output if one switches the order of the two statements 
	inside the while() loop?

3. Write a C program to print out the following nine lines of *'s:
	(Hint: you may consider to use while loops)

z: a.out
***
**
*
**
****
******
  *
 **
***
z: 

4. Write a program that asks user to input an integer x and decides whether
   x is positive or negative. Your program should stop when 0 is entered. 
   For example,

z: a.out
Enter an integer (0 to stop): -2
-2 is negative.
Enter an integer (0 to stop): 531
531 is positive.
Enter an integer (0 to stop): 0
You entered 0. Good-bye!
z:

5. Complete the following program so it will replace a character in the
   given sentence

#include<stdio.h>

int main(void)
{ char s[] = "thisismyfirsthomeworkinENEE114";
  .....
  printf("Here is a sentence:\n%s\n", s);
  printf("Enter the position that you want to replace (0 to 29):");
  ....
}

  For example, the following shows the output of the completed program
  when the first i is replaced by t, 

z:a.out
Here is a sentence:
thisismyfirsthomeworkinENEE114
Enter the position that you want to replace (0 to 29):2
Enter the character that you want to replace 'i':t
Here is the new sentence:
thtsismyfirsthomeworkinENEE114
z:


6. Write a complete C program to ask the user to enter the number of
	quarters, dimes, nickels, and pennies and then create an output
	like the following:

You have entered 2 quarters, 3 dimes, 4 nickels, and 1 pennies.
There are 10 coins and their total value is $1.01.

  (Note: all coin names (quarters, dimes, nickels, and pennies) will be 
	in plural even if you have 1 or none coin of that kind.)