school_archives/OSU Coursework/CS 161 - Intro to Programming I/Assignments/Assignment 1/written/perrenc_hw0.txt

1 - What does a comment in C look like? Give some examples.

/** This is what the majority of block comments in C look like. Once it is
 * recognized as a comment, the block color will change for easier
 * readability.
 */	

// This is an example of a single line comment. It's useful for commenting on
// the same line as actual code.


2 - How does one open a file in vi? Save a file? Quit?

	a. To open a file, you type "vi filename" at the linux command line.
	   To save a file, enter vi command mode and type ":w"
	   To quit, enter vi command mode and type ":q" or press shift-z-z  


3 - (3.1) Write the octal, decimal, and  hexadecimal equivalents of these numbers.
      Answers in form "Original: octal, decimal, hexadecimal"
	
	a. 00110011 = 63, 51, 33
	b. 01101100 = 154, 108, 3C
	c. 01110111 = 167, 119, 77
	d. 00111101 = 75, 61, 3D
	e. 11111011 = -5, -5, -5
	f. 11111111 = -1, -1, -1
	g. 00100010001011010 = 42132, 17498, 445A
	h. 10100010001011010 = -135646, -48038, -BBA6


4 - (3.5) Find the errors in each of the following segments.
	a. printf("%s\n", 'Happy Birthday'); 
		Fixed: printf("%s\n", "Happy Birthday");

	b. printf("\%c\n", 'Hello');
		Fixed: printf("%s\n", "Hello");

	c. printf("%c\n", "This is a string);
		Fixed: printf("%s\n", "This is a string");

	d. printf(""%s"", 'Good Bye');
		Fixed: printf("%s", "\"Good Bye\"\n");

	e. char c = 'a';
	   printf("%s\n", c);
		Fixed: char c = 'a';
		       printf("%c\n", c);

	f. printf('Enter your name: ");
		Fixed: printf("Enter your name: ");

	g. printf( %f, 123.456);
		Fixed: printf("%f", 123.456);

	h. printf("%s%s\n", 'O', 'K');
		Fixed: printf "%s%s\n, "O", "K");

	i. char c;
	   scanf("%c", c);
		Fixed: char c;
		       scanf("%c", &c);

	j. double d;
	   scanf("%f", &d);
	   printf("%f", d);
		Fixed: double d;
		       scanf("%lf", &d);
		       printf("%lf", d);

	k. int d;
	   scanf("%f", &d);
	   printf("%f", d);
		Fixed: int d;
		       scanf("%d", &d);
		       printf("%d", d);

	l. double x = 123.45678, y;
	   int d;
	   d = x;
	   y = d;
	   printf("%f\n", y);
		Fixed: double x = 123.45678
		       double d;
		       d = x;
		       y = d;
		       printf("%f\n", y);


5 - (3.6) How many digits are after the decimal point for floating point values
printed with printf? Does printf round or truncate values?

	a. There are six values after the decimal point by default. Yes,
	   printf will always truncate to this number unless otherwise specified, and
	   while doing so, it rounds the answer.


6 - (3.17) Signed and unisgned representation problems
	a. Signed - 256
	   Unsigned - 128
	b. Signed - 65536
	   Unsigned - 32768
	c. Signed - 4294967296
	   Unsigned - 2147483648
	d. Signed - 64
	   Unsigned - 32
	e. Signed - 1024
	   Unsigned - 512


7 - (4.1) State whether the following are true or false?

	a. False. Operators in C are evaluated from right to left. The
	   compiler reads down the code, the evaluates coming back up in the opposite
	   direction. 

	b. False. The || operator is an inclusive or, meaning that if either
	   or both of the operator statements are true, the expression will evaluate as
	   true.


8 - (4.12) - Write C Expressions

	a. (x + 4) / (y + 5)
	b. 9 + (5*((x + 4) / (y + 5)))
	c. (4 / 3) * 3.14 * r pow(r, 3)
	d. x < y
	e. (x >= y) & (y <= z)
	f. (x >= y) & (x >= 0)
	g. (x <= 1) | (x > 20)
	h. (x > 1)  & (x <= 20)
	i. ( (x > 1) & (x <= 20) ) | ( (y <= 3) & (y >= 1) )


9 - (5.3) Correct errors in each of the code blocks

	a. if(age >= 65);
	   	printf("Age is greater than or equal to 65\n");
	   else
	   	printf("Age is less than 65\n")
		
	a fixed: if(age >= 65){
           	        printf("Age is greater than or equal to 65\n");
           	 }else{
                	printf("Age is less than 65\n");
		 }


	b. if(i = 2)
	   	printf("i is 2\n");
	   else
	   	printf("i is not equal to 2\n");

	b fixed: if(i == 2){
                 	printf("i is 2\n");
           	 }else{
                	printf("i is not equal to 2\n");
		 }


	c. for(x = 999; x >= 1; x +=2)
	   	printf("%d\n", n);

	c fixed: for(int x = 999; x >= 1; x -=2){
                 	printf("%d\n", x);
		 }


	d. counter = 2;
	   Do {
	   	if(counter % 2 == 0)
			printf("%d\n", counter);
			counter += 2;
	   }While(counter < 100)

	d fixed: counter = 2;
                 while(counter < 100){
                 	if((counter % 2) == 0){
                        	printf("%d\n", counter);
                        	counter += 2;
				}
           	 }


	e. total = 1;
	   for(x = 100; x <= 150; x++);
	   	total += x;

	e fixed: total = 0;
		 for(int x = 100; x <= 150; x++){
		 	total += x;
		 }