comp115/155 past paper questions (1 Viewer)

[...]

http://teaching.ics.mq.edu.au/units/comp155/paper.pdf

2. 20 marks in total
(a) (4 marks) Complete the following function which when given an integer will return
true if the integer is negative and otherwise false. WRITE ONE LINE ONLY.
bool isNegative(int n)
{ // supply this code - write ONE line only
}
(b) (8 marks) Complete the following function that will determine and return the smallest
of three supplied integer values. Supply only the missing lines.
int minValue(int a, int b, int c)
{ //supply this code

umm..i have no idea what do to with bool functions

any help is appreciated!

 

[doe]

ok

it may help you to remember that bool's are basically just integers with 0 being false and non zero (ie positive or negative) being true. yes, this means that if (-1) will be true (try it and see for yourself).

for q 2a)

return(n < 0);

qb)

theres a gagillion ways to do this, id just use the builtin min() function, or write your own.

return(min(a, min(b, c)));

min() is easily written as

int
min(int a, int b)
{
&nbsp;&nbsp;&nbsp;&nbsp;return(a < b ? a : b);
}

or

int
min(int a, int b)
{
&nbsp;&nbsp;&nbsp;&nbsp;if (a < b)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return(a);
&nbsp;&nbsp;&nbsp;&nbsp;return(b);
}

&nbsp;

 

[eyebrowman]

unrelated to topic but..

can someone post the MC answers for the exam plz?

 

[...]

hmm..another one

=D
(b) (10 marks) Write a function in C++ that when given an integer array A and its size
n will determine if all the items in A[0..n-1] are sorted in non-descending order.
For example if A contains 1,2,2,3,7,7,9 then A is in non-descending order and the
function should return true. Note that non-descending order means that each item
is less than or equal to all the items which follow it.
bool isSorted(int A[], int n)
/* pre : A[0..n-1] is an array of ints
post : returns true if A[0..n-1] is sorted in non-descending
order and otherwise false
{ \\ complete this code

this is my solution..i think i screwed it

for (i = 1; i <= n - 1; i++)
if ( a[0] < a)
return true
else
return false

 

[doe]

for (i = 1; i < n; i++){
&nbsp;&nbsp;&nbsp;if (a < a[i-1])
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return(false);
}
return(true);

 

[...]

blah, just made an arse of myself..lol

 

[doe]

hehe

noone comes out of the womb knowing this stuff, everyone has to learn it sometime (well, everyone who does comp at least)

 

[boinkBOINK]

shows how much im gonna fail comp

 

[redruM]

what are going to be the toughest questions??

 

[...]

another question

(a) (10 marks) Write a function in C++ that when passed a string S and a character ch
will return the number of times ch occurs in S. There are some useful string functions
in the Appendix.
int occurrences (string S, char ch)
/* pre : none
post : returns a count of the number
of times ch occurs in S */
{ // complete this code


(10 marks) Complete the following function that when passed a string (not containing
any blanks) will determine if the string is a palindrome. Recall that a string is a
palindrome if it is the same when reversed. For example madam, noon, and radar
are palindromes whereas madman is not. You may assume that the string contains
only lower case letters. There are some useful string functions in the Appendix.
bool isPalindrome (string s)
/* pre : none
post : returns true if s is a palindrome
and otherwise false */
{ // complete this code



for c) i can do it if the integer input is numbers, not characters like abc

 

[doe]

a)

count = 0;
for (i = 0; i < s.length() i++) {
&nbsp;&nbsp;&nbsp;&nbsp;if (s.at(i) == ch)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count++;
}
return(count);

palindrome:

isPalindrome(string s)
{

if (s.length() <= 1)
&nbsp;&nbsp;&nbsp;&nbsp;return(true);

//if 1st char matches last char
if (s.at(0) == s.at(s.length() - 1))
&nbsp;&nbsp;&nbsp;&nbsp;return(true && ispailindrome(s.substr(1, s.length() - 2)));
//they dont match, not a palidrome
return(false);
}

or something

 

[doe]

you could actually make that last one:

isPalindrome(string s)
{
if (s.length() <= 1)
&nbsp;&nbsp;&nbsp;&nbsp;return(true);
return((s.at(0) == s.at(s.length() - 1)) && ispalindrome(s.substr(1, s.length() - 2)));
}

... hehe

 

[Orange Juice]

anyone done the mc's yet?

 

[...]

Originally posted by Orange Juice
anyone done the mc's yet?

yea..

i did around 25 of them

the rest i have to read the textbook

haha

 

[Orange Juice]

i could only do 23!
triple D post your answers up...
i dont want to post mine if everyone else compares em and stuffs up

 

[...]

1.E
2.C
3.C
4.D
5.C
6.E
7.D
8.C
9.B
10.A
11.B
12.A
13 D <==i thnk
14.B
15.A
16 D <==i thnk
17 <==need to read the text
18.D
19.D
20.D
21.B
22.D
23.A
24.B
25.B
26.C
27
28.E
29
30

 

[Orange Juice]

how did you do 9 and 10?
q12 i got d
q16 i got e
what did you get for 17?
i see a smiley

 

[...]

9 was posted in here somewhere

basically its finding wat statment is the table relating
ah shit, 16 u got it right

and as for 12, i dunno..like both seems right.. =\

 

[Orange Juice]

oh... and 25 26... dunno how to do those

 

[doe]

where are the questions?