Using switch statement and while loop in conjunction - matlab

Question

I am trying to complete the following task:
Create
a
script
that
will
repeatedly
create
a
random
integer
K
in
the
range
of
0
to
20
until
every
case
has
been
entered
at
least
once.
You
have
3
possible
cases.
Case
A
is
entered
when
the
range
of
the
random
integer
K
is
between
or
equal
to
0
and
7.
Case
B
is
entered
when
the
range
of
the
random
integer
K
is
between
or
equal
to
8
and
14.
Case
C
is
entered
when
the
range
of
the
random
integer
K
is
between
or
equal
to
15
and
20.
Rules:
When
a
case
is
entered
you
must
print
to
the
user
“Congratulations
you
entered
Case
(A,
B,
or
C)”.
You
can
only
enter
each
case
once.
If
the
program
attempts
to
enter
the
same
case
more
than
once,
you
must
print.
“Invalid,
that
case
has
already
been
entered”.
The
program
will
end
once
all
the
cases
have
been
entered
and
the
program
will
print
“Good
job,
you
have
entered
all
cases”.
If
the
program
attempts
to
enter
any
already
entered
cases
more
than
3
times
(3
total
times
not
just
for
one
specific
case),
the
program
will
end
and
print
to
the
user
“That
random
generator
wasn’t
random
enough”.
Here is the code I have so fa. It has taken me a couple hours to debug. Am I approaching this the wrong way????Please let me know.
K = round(rand*(20))
flag = 0;
counterA =0;
counterB=0;
counterC=0;
switch K
case {0,1,2,3,4,5,6,7}
fprintf('Congratulations you entered Case A\n')
flag = 1;
counterA = 1
case {8,9,10,11,12,13,14}
fprintf('Congratulations you entered Case B\n')
flag =2;
counterB = 1
case {15,16,17,18,19,20}
fprintf ('Congratulations you entered Case C\n')
flag = 3;
counterC = 1
end
while flag == 1 || flag == 2 || flag ==3
K = round(rand*(20))
if K >=0 && K<=7 && flag==1
disp ('Invalid, that case has already been entered')
counterA = counterA+1
elseif K >=8 && K<=14 && flag ==2
disp ('Invalid, that case has already been entered')
counterB=counterB+1
elseif K >=15 && K<=20 && flag==3
disp ('Invalid, that case has already been entered')
counterC =counterC+1
elseif K >=0 && K<=7 && flag ~=1
counterA =counterA+1
flag == 1;
if counterA==1&&counterB~=2 ||counterA==1&&counterC~=2
fprintf('COngrats guacamole A\n')
end
elseif K >=8 && K<=14 && flag ~=2
counterB=counterB+1
flag == 2;
if counterB ==1&&counterA~=2||counterB==1&&counterC~=2
fprintf('COngratsavacado B\n')
end
elseif K >=15 && K<=20 && flag~=3
counterC=counterC+1
flag == 3;
if counterC==1&&counterA~=2||counterC==1&&counterB~=2
fprintf ('Congratscilantro C\n')
end
end
if counterA==1 && counterB==1 && counterC==1
flag=100;
disp('DONE')
elseif counterA == 3|| counterB==3 || counterC==3
disp ('That random generator wasnt random enough')
flag =99;
elseif counterA==2||counterB==2||counterC==2
disp('Inval')
end

Answer 1

Some words about your code:
Don't use variable names like counterA,counterB,counterC, use a array with 3 elements instead. In this case: You need only a total limit, thus one variable is enough.
rand*20 generates random values between 0 and 20, but using round(rand*20) causes a lower probability for 0 and 20. Use randi if you need integers.
Use "Start indent" to format your code clean, it makes it easier to read.
This is not a full solution, the part with the 3 errors is missing. I think you will get this on your own.
caseNames={'A','B','C'};
caseEntered=[false,false,false];
%while there exist a case which is not entered and limit is not reached, continue
while ~all(caseEntered)
K = randi([0,20]);
switch K
case {0,1,2,3,4,5,6,7}
cs=1;
case {8,9,10,11,12,13,14}
cs=2;
case {15,16,17,18,19,20}
cs=3;
end
if caseEntered(cs)
%case has previously been entered, tdb
else
%case is entered frist time
fprintf('Congratulations you entered Case %s\n',caseNames{cs});
caseEntered(cs)=true;
end
end