Introduction to computer science 2 (csca48) notes + exercises + midterm

CSCA48"




duf

, Unit #1 -
Intro.doesn't have
interactive mode
needs compile :
for Syntax
code- code (also checks
~

empileid
/
: source


does something

human understandable P
-T imperative
I : step by Step-how program
High level understanding
:
simple : more focus on

[ EY
-




Low level
: machine
ciese language -

how computer works
-
need to know details
return o; successful running & # include stdio h
include and use code from
.




Libraries :
program can
23
Delimiters : code that belongs to a specific scope
'a' or
:

Comments in Al 11 e'$' or
in ar , void
:
or

Fundamental data types ,
floats double ,
: int

Variables are local t that function -




·
In : new line
Collection
GCC :
GNU compiler

file . - file- new
Specify Name :
gcc

quotes only
"
Use double
Errors
( missing ;I
Common :


of "I "

before return Is I instead
.




-

expected';" for itstype
constant too long
before string constant
char
-warning :
or ...
-

expected declaration specifers
I printf a fer ? %ht 3 . 145)
fr variables
,
:
p pointer
Format specifiers %C Char is string => 5 . 15

%f float
decimal 2 %at 5 1)
Yd sci notation
.

,
num using 14
floating point
= 3 .




% g
Control Sequences % print of
Common 1) print
It tab
In new line
while
il;3 for loop
updates printf("Yd"
Y
,

i readability
:
· Loops condition
for Lintialization ;
2) less code , less
For loops bugs
while loops
·
conditional Statements
if and else
( = , , >, =, =, !
operators
=


Comparison
·
88 !
Common
· logical Operators (11 ,




E
specify
decimal to 2 Check square approach
%. If :

one loop

func
-




·

Running : -iss
guare
x-wall-sta 199-file -oname .
- nested loop
= .




g break ;
-

while loop

on
laptop

,Un -
Model Runs

squarell gets
in
AM
erased

TerTeddy
Note :
<int square()
int square (intx]3 main -2)
.




Fi
m
-
= I

⑮put Geturr E




↑·
E
int si put -


S =


return s;
X D
xi
E into Lint
(local var)



int main()S
int input ; Global
int output;
in put = 7 ;

output =
square(inputt ; 3
the value for arguments
-
pass
by value making : a
copy of input
- -


Scope where variable can be referenced and manipulated
local variable scope
:


(input para and
-




variable between curly brackets
Local variable :



(difficult to debug
-




Global variable : can be used by all functions .




·
-




E [
int Xa 114 in y
=
113 - Note :


int square (15 25 3/n
-




Passing array
or pointer
X= X * X; 3 [int >
don't
main()E < global >
to function , you
a
int
are fixed .
need to reassign them
59 Data types
1 =




square) ; 3


⑫
as they are references
.

~
O X 2
.



g
-
reverse (array)
-




Type casting "
I 5/2 reversecarray X
=
result array =
int y: X ,
=
2 asint (x , y)
float result : 5
0 as float
result
enough) to get :So
=
2
Gresult
.



is
X/y ; =

[int] Lints <float > cast float() Cone
X = 5 % you can type
y
=
29
int
210] ;
-read and store values array
IOD
Array e
g
.
:
-




- non-extendable T


O to 1
n
type
-



same
-




-
all entries must have
NO WARNING for outside indexing
=
-




string
: char sing[1020]
tri :
end oftring deliminator
-




string [O] 'It's :
strings are properly terminated
compiler adds it to ensure
string [1] 10:
=


OR USE



J
# include <string he (variable "Store this") ;
eg strcpy
.




string
,


intialize a
Strcpyc
· :

strcat(variable, "also this") ;
result :



str cat)) concatenate strings e g alsothis
.
.


:
·
printf("s" variable); > store this
,


· strlen() : len of a string egstulen (var) ;
equal stremp (varl varz) ;
strings and returns if e.g ,
·
strempC :
compares 2 o
if var1 < var2 then - -

- Pointer : variable that contains memory address
.
if var 1 .
) var 2 then - +
= = var2
-
> 0
address of if vari
-
S :
get memory
intialize pointera contents of
-intap; dereference a pointer dereference
and change
&:

address (1)
then
- * (-- p) = 12 ; change memory
value
-
var =
Ap ; var stores p's

, Unit #2

declare
van is 18
My int
-address of int s
1 15
de referencing My
int is 21
My




1
m
Note :




Imp things to remember
① Always NULL
set pointer =



NULL
Check
② if pointer is
will crash
or
program
data from
Make sure accessing
③
Q ⑤ P index
.
pointers is within
# Arrays are passed as pointers
.
↑3 I %
NOLL


int > int >
L Listin




Set second of to 10
entry array

Main
↑
(p + 1) = 10 %


prese
o
g
_




-
-
compiler



Exercises
.

Ex 1 Reverse string #define MAX 1027 int main()




I
word [MAX] ;
void reverse (char word(s) char

Stropy (word , "Joe") ;
int length strenword
=




(word) ; them
for (inti = 0 ; i < length/2 ; it s reverse / for arrays you don't reassign
11 word reverse (word) ; is wrong
.
char temp word[i] ;
e
g
.


=




word[i] =
word length-i-I ;
word[length 1-i] = temp
;
-




Ex Takes array , query target chars and replaces query
, w
targetchar
void replace (char word [] , char query , char targets

intlenstenworda
if(word (i) ==
query)3
word[i] =
targets
3