CMSI 182 - Introduction to Computer Science

Week 2

References

Biermann's class notes:

Examples

a small decision tree

program curious;
uses WinCrt;
var
   answer : string;
begin
writeln('Are you curious?');
readln(answer);
if answer = 'yes' then
   begin
   writeln('Good.');
   end
else
   begin
   writeln('Too bad.');
   writeln('I had hoped you would be.');
   end;
end.

a larger decision tree

program goingOut;
uses WinCrt;
var
   answer1, answer2, answer3 : string;
begin
writeln('Do you enjoy movies?');
readln(answer1);
if answer1 = 'yes' then
   begin {enjoys movies}
   writeln('Are you a SF fan?');
   readln(answer2);
   if answer2 = 'yes' then
      begin
      writeln('I recommend Insurrection.');
      end
   else
      begin
      writeln('I recommend Varsity Blues.');
      end;
   end
else
   begin {no movies}
   writeln('Do you like dining out?');
   readln(answer3);
   if answer3 = 'yes' then
      begin
      writeln('I recommend Bruno''s Ristorante.');
      end
   else
      begin
      writeln('I recommend bowling.');
      end;
   end;
end.

the assignment statement

program switch;
uses WinCrt;
var
box1, box2, temp : integer;
begin
readln(box1);
readln(box2);
temp := box1;
box1 := box2;
box2 := temp;
writeln(box1, ' ', box2);
end.

concatenating strings

program hanSolo;
uses WinCrt;
var
s, t, u : string;
begin
s := 'Chew' + 'bacca';
s := 'Han';
t := s + ' Solo';
s := 'Leia';
readln(u);
u := u + ' ' + s;
writeln(t, ' and ', u);
end.

page 48 Exercise 1

program doubleString;
uses WinCrt;
var
s : string;
begin
writeln('Please enter a string of symbols.');
readln(s);
writeln('The string doubled is ', s + s + '.');
end.

page 48 Exercise 2

program plural;
uses WinCrt;
var
noun : string;
begin
writeln('Please enter a noun.');
readln(noun);
writeln('The plural of your noun is ', noun + 's.');
end.

integer and string data types

program types;
uses WinCrt;
var
i, j, k : integer;
s, t, u : string;
begin
i := 1;
j := 2;
k := i + j;
s := 'no';
t := 'ne';
u := s + t;
writeln(i, ' ', j, ' ', k, ' ', s, ' ', t, ' ', u);
end.

integer and string operators

program operators;
uses WinCrt;
var
   i, j, k : integer;
   s, t, u : string;
begin
{ integers }
i := 1;
j := 2;
if i < j then { comparison }
   begin
   writeln(i, ' is less than ', j);
   end;
k := i + j + 3; { addition }
k := i * j;      { multiplication }
k := i div j;    { division - drops any remainder}

{ strings }
s := 'no';
t := 'ne';
if s > t then { comparison }
   begin
   writeln(s + ' is greater than ' + t);
   end;
end.

page 51 Exercise 1

program positive;
uses WinCrt;
var
   n : integer;
begin
writeln('Please enter an integer.');
readln(n);
if n > 0 then
   begin
   writeln(n, ' is positive.');
   end
else
   begin
   writeln(n, ' is not positive.');
   end;
end.

Homework

p. 33 Exercise 2

Your decision tree should have a depth of 3 - i.e. it should have three columns/levels.
When you save your file the File Save As box should appear as follows:

File name mytree.pas
Path: U:\cmsi182\yourAcct

p. 48 Exercise 3

When you save your file the File Save As box should appear as follows:

File name address.pas
Path: U:\cmsi182\yourAcct

p. 51 Exercise 2

When you save your file the File Save As box should appear as follows:

File name arith.pas
Path: U:\cmsi182\yourAcct

Just For Fun

http://teamhouse.tni.net/mil2000.htm

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Last Modified January 17, 2000
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