COMP1604 COMPUTER SCIENCE, AUTUMN EXAMINATIONS 2003 SOLUTIONS

1.(a) True

  (b) False (comments are optional in C)

  (c) False (logic errors are not detected by the C compiler)

  (d) value of w is 6

  (e) value is 2.24

  (f) error case

  (g) condition is false

  (h) i is 6
      i is 1

  (i) default
      default
      2
      3
      default

  (j) correct answer is (j-3)  it returns an integer value to
       the calling function.

  (k) correct answer is (k-1)  fname() takes 1 argument of type
       pointer-to-int and returns a value of type float.

  (l) result is -16

  (m) correct answer is (m-2)  arrints[0]+arrints[1]

  (n) True

  (o) element number 1 is 1
      element number 2 is 2
      element number 3 is 3
      element number 4 is 0
      element number 5 is 0

  (p) correct answer is (p-3)  y = *ptr1;

  (q) x is -1 and y is -2

  (r) False (the name of a string is treated by the C compiler as a
       fixed pointer-to-char whose value is the address of the first
       array element and which cannot be reassigned)

  (s) string=YbcdYfghYjklmn

  (t) correct answer is (t-2)  if it exists, open datafile.txt for
       reading only, otherwise return an error.


2.(a)	int i;
	char string[100];
	/* assume string[] is somehow filled with letters, digits, etc */
	for (i=0; string[i]!='\0'; i++){
	   if ((string[i] >= 'a') && (string[i] <= 'z')){
	      printf("%c", string[i]);
	   }
	}

  (b)	if (price>=20){
	   printf("Sell\n");
	} else if (price>=10){
	     printf("Hold\n");
	  } else {
	       printf("Buy\n");
	    }

  (c) int numneg(int array[], int size){
         int i, k=0; /* i is a local loop counter */
         for (i=0; i<size; i++){
            if (array[i]<0){
               k++;
            }
         }
	 return (k);
      }


3.(a) LINE 1: scanf("%d", intarr+i);
      LINE 2: printf("you entered %d\n", *(intarr+i));

  (b)(i) "hello there" has length 11

   (ii)	#include "stdio.h"
	void main(void){
	  char message[80]="hello there";
	  int stringlength(char str[]); /* function prototype */
	  /* or: put stringlength() before main() */
	  printf("\"%s\" has length %d\n", message, stringlength(message));
	}
	int stringlength(char s[]){ /* no need to pass in size of array */
	  int count=0;
	  while (s[count]!='\0'){
	    count++; /* increase by 1 as long as NULL not reached */
	  }
	  return count;
	}