Programming PascalABC. Why is "output" without any text? - pascal

Even just in the middle of the program I inserted "write (OutPut, '2');" and even at the very end it is, but the "output" file is still created empty.
program HelloFromRussia;
var
s, y, h, n, x: Integer;
InPut, OutPut: Text;
begin
assign(InPut,'c:\input.txt');
assign(OutPut,'c:\output.txt');
reset(InPut);
rewrite(OutPut);
read(InPut, y);
write(OutPut, '1');
for var i:=1 to y do
begin
read(InPut, s);
if s mod 2 = 0 then write(OutPut, s, ' ');
end;
writeln(OutPut);
reset(InPut);
read(InPut, y);
for var i:=1 to y do
begin
read(InPut, s);
if s mod 2 <> 0 then writeln(OutPut);
write(OutPut, s, ' ');
end;
for h:=1 to y do begin
if s mod 2=0 then
n:=n+1;
if s mod 2<>0 then
x:=x+1;
end;
if (n>x) then writeln(OutPut, 'YES')
else writeln(OutPut, 'NO');
write(OutPut, '2');
close(InPut);
close(OutPut);
end.

Related

Not understanding array merging procedure in merge sort procedure

I've been trying to learn the procedure for merging two arrays in merge sort, and I've been given a fixed code which I have to strictly follow .The following is a program for sorting a list of numbers in ascending/ descending order depending on the user's choice is as follows:
const
max = 200000;
MaxDisp = 20;
type
list = array[1..max] of real;
var
a: list;
na: longint;
is_asc:boolean;
procedure GenList(var L: list; n: longint);
var
i: longint;
begin
randomize;
for i := 1 to n do begin
L[i] := random;
end;
end;
procedure DispList(L: list; n: longint);
var
i: longint;
begin
for i := 1 to MaxDisp do begin
if i <= n then begin
writeln(i:10, ' - ', L[i]:0:10);
end;
end;
if n > MaxDisp then begin
writeln(n - MaxDisp, ' more ...');
end;
end;
procedure sort(var L: list; n: longint;is_asc:boolean);
procedure Merge(L1,L2,R1,R2:longint);
var
M:list;//this is C
i1,i2,iM,i,j:longint;
begin
i1:=L1;
i2:=L2;
j:=1;
while (i1<=R1) and (i2<=R2) do begin
if (is_asc and (L[i1]<L[i2])) or not is_asc and (L[i1]<L[i2]) then begin
M[j]:=L[i1];
j:=j+1;
i1:=i1+1;
end
else begin
M[j]:=L[i2];
j:=j+1;
i2:=i2+1;
end;
j:=________;
end;
if(i1>R1) and (i2<=R2) then
for i:=________ do begin
M[j]:=_______;
end
else if (i2>R2) and (i1<=R1) then
for i:=1 to _______ do begin
_________;
end;
num:=_______;
i:=______;
for j:=1 to num do begin
_________;
end
end;
procedure MSort(LL,RR:longint);
var mid:integer;
begin
if LL<RR then begin
mid:=(LL+RR) div 2;
MSort(LL,mid);
MSort(mid+1,RR);
Merge(LL,mid,mid+1,RR);
end
end;
begin
MSort(1,n);
end;
function is_sorted(L: list; n:longint;is_asc:boolean): boolean;
var
i: longint;
flag: boolean;
begin
flag := true;
i := 1;
while flag and (i < n) do begin
flag := ((L[i]<=L[i+1]) and (is_asc)) or (not(is_asc) and (L[i]>=L[i+1]));
i := i + 1;
end;
is_sorted := flag;
end;
begin
na := MaxDisp;
GenList(a, na);
writeln(na, ' random items:');
DispList(a, na);
writeln('Press <Enter> to sort the list in ascending order ...');
readln;
sort(a, na,is_asc);
DispList(a, na);
writeln('Sorted in ascending order: ', is_sorted(a, na,is_asc));
write('Press <Enter> to continue ...');
readln;
end.
Except for the blank parts, I understand what the other parts of the code are doing, including the first part of the procedure Merge, which I think is just merging the arrays in L into M, and I think the following part is writing about the cases in case i1 and i2 are larger than L1 and L2, but I don't understand what the problem if this happens or what should be done. After this the following parts of the procedure Merge I have no idea what it is supposed to be doing.
I don't know this language (indexes start at 1?), but this is what I think needs changing:
i1:=L1;
i2:=L2;
j:=1;
while (i1<=R1) and (i2<=R2) do begin
if (is_asc and (L[i1]<L[i2])) or not is_asc and (L[i1]<L[i2]) then begin
M[j]:=L[i1];
j:=j+1;
i1:=i1+1;
end
else begin
M[j]:=L[i2];
j:=j+1;
i2:=i2+1;
end;
// j:=________; // don't change j
end;
while(i1 <= R1) do begin // copy rest of run 1 if any elements
M[j]:=L[i1];
j:=j+1;
i1:=i1+1;
end
while(i2 <= R2) do begin // copy rest of run 2 if any elements
M[j]:=L[i2];
j:=j+1;
i2:=i2+1;
end
for(i = 1 to j) do begin // copy M back into L
L[i+L1-1] := M[j]; // I'm not sure about the -1
end
end;

What's wrong with max values of GotoXY function?

My code is doing strange thing when MoveMessage procedure takes max values(ScreenWidth and ScreenHeight). So the "Hello, world" string moves to the right down corner and doing strange thing, but the max and min values are set correctly.
Can someone tell me where is my mistake.
program HelloCrt;
uses crt;
const
Message = 'Hello, world!';
procedure GetKey(var code: integer);
var
c: char;
begin
c := Readkey;
if c = #0 then
begin
c := Readkey;
code := -ord(c);
end
else
code := ord(c);
end;
procedure ShowMessage(x, y: integer; msg: string);
begin
GotoXY(x, y);
write(msg);
GotoXY(1, 1);
end;
procedure HideMessage(x, y: integer; msg: string);
var
len, i: integer;
begin
len := Length(msg);
GotoXY(x, y);
for i := 1 to len do
write(' ');
GotoXY(1, 1);
end;
procedure MoveMessage(var x, y: integer; msg: string; dx, dy: integer);
begin
HideMessage(x, y, msg);
x := x + dx;
y := y + dy;
if x > (ScreenWidth - length(msg)) then
x := (ScreenWidth - length(msg) + 1);
if x < 1 then
x := 1;
if y > ScreenHeight then
y := ScreenHeight;
if y < 1 then
y := 1;
ShowMessage(x, y, msg);
end;
var
CurX, CurY: integer;
c: integer;
begin
clrscr;
CurX := (ScreenWidth - length(Message)) div 2;
CurY := ScreenHeight div 2;
ShowMessage(CurX, CurY, Message);
while true do
begin
Getkey(c);
if c > 0 then
break;
case c of
-75:
MoveMessage(CurX, CurY, Message, -1, 0);
-77:
MoveMessage(CurX, CurY, Message, 1, 0);
-72:
MoveMessage(CurX, CurY, Message, 0, -1);
-80:
MoveMessage(CurX, CurY, Message, 0, 1);
end
end;
clrscr;
end.

procedures don't work properly when dealing with files in pascal

In this program when I try to put the code blocks [1] and [2] in procedures they don't work properly when calling them, and when I keep them in the main program only the first one works properly and the second doesn't and when I comment out the first one the second one works as it's supposed...can you please spot the error, I think it's with getting the files names from the user cause when I choose the file's name it works properly
program Linked_lists_files;
type
Node = ^T;
T = record
num : integer;
next : Node;
End;
var
File1 : Text;
N, i, j, cmp, y, x, Num, matrixvalue : integer;
Head, Tail, Head2, Tail2, Head3, Tail3 : Node;
s : string;
matrix : array [1..20, 1..20] of Integer;
// procedures
// [1]
Procedure fillFile();
Begin
write('Input file name to create : ');
readln(s);
assign(File1,s);
rewrite(File1);
Repeat
write('Enter a number : ');
readln(N);
if (N>=0) then
writeln(File1, N);
Until (N<0);
close(File1);
End;
// [2]
Procedure GetFromFile();
Begin
cmp := 0;
write('Enter file name to read from : ');
readln(s);
assign(File1, s);
reset(File1);
while not eof(File1) Do
Begin
readln(File1, N);
if (Head = Nil) then
Begin
new(Head);
Tail := Head;
End
Else
Begin
new(Tail^.next);
Tail := Tail^.next;
End;
Tail^.num := N;
Tail^.next := Nil;
cmp := cmp + 1;
End;
Close(File1);
Write('Elements of the list : ');
Tail := Head;
if (Head<>nil) then
Begin
while(Tail <> nil) Do
Begin
write('[',Tail^.num,']', ' ');
Tail := Tail^.next;
End;
End
Else
Writeln('[!] The list is empty');
writeln;
writeln('Number of elements in the list : ', cmp);
End;
// [3]
Procedure SaveFromFile();
Begin
Head := Nil;
write('Enter file name to read from : '); readln(s);
writeln('[+] Fill in your list');
Repeat
write('+ Enter an integer : ');
read(y);
if (y>=0) then
Begin
if (Head = Nil) then
Begin
new(Head);
Tail := Head;
End
Else
Begin
new(Tail^.next);
Tail := Tail^.next;
End;
Tail^.num := y;
Tail^.next := Nil;
End;
Until y<0;
assign(File1, s);
rewrite(File1);
Tail := Head;
while(Tail <> nil) Do
Begin
Num := Tail^.num;
Tail := Tail^.next;
Writeln(File1, Num);
End;
Close(File1);
Writeln('[+] Elements of the lists have been successfully added to the new file');
End;
// [4]
Procedure SquareMatrix();
Begin
cmp := 0;
x := 0;
writeln('[+] Fill in your list');
Repeat
write('+ Enter an integer : ');
read(y);
if (y>=0) then
Begin
if (Head3 = Nil) then
Begin
new(Head3);
Tail3 := Head3;
End
Else
Begin
new(Tail3^.next);
Tail3 := Tail3^.next;
End;
Tail3^.num := y;
Tail3^.next := Nil;
cmp := cmp + 1;
End;
Until y<0;
while (cmp<>1) Do
Begin
if (cmp mod 2 <> 0) and (cmp <> 1) then
x := x + 1;
cmp := cmp div 2;
End;
if (x>0) then
writeln('[-] False')
Else
writeln('[+]True');
End;
// [5]
Procedure ElementsOfSM();
Begin
cmp := 0;
x := 0;
writeln('[+] Fill in your list');
Repeat
write('+ Enter an integer : ');
read(y);
if (y>=0) then
Begin
if (Head = Nil) then
Begin
new(Head);
Tail := Head;
End
Else
Begin
new(Tail^.next);
Tail := Tail^.next;
End;
Tail^.num := y;
Tail^.next := Nil;
cmp := cmp + 1;
End;
Until y<0;
Tail := Head;
i := 1;
j := 1;
while(Tail <> nil) Do
Begin
matrixvalue := Tail^.num;
matrix[i,j] := matrixvalue;
Tail := Tail^.next;
j := j + 1;
if (j = sqrt(cmp)+1) then
Begin
i := i + 1;
j := 1;
End;
End;
for i:=1 to cmp Do
for j:=1 to cmp Do
Begin
if (matrix[i,j]<>0) then
writeln('[',matrix[i,j],']',' : ','[',i,',',j,']');
End;
End;
// [6]
Procedure Element();
Begin
write('Enter the number of the line : ');
read(i);
write('Enter the number of the column : ');
read(j);
write('The element corresponding to ','[',i,',',j,'] is : ','[',matrix[i,j],']');
writeln;
End;
// [7]
Procedure WriteP();
Begin
write('Enter the number of the line : ');
read(i);
write('Enter the number of the column : ');
read(j);
write('Enter the value you want to pass in : ');
read(N);
matrix[i,j] := N;
writeln('The new matrix');
for i:=1 to cmp Do
for j:=1 to cmp Do
Begin
if (matrix[i,j]<>0) then
writeln('[',matrix[i,j],']',' : ','[',i,',',j,']');
End;
writeln;
End;
// [8]
Procedure Content();
Begin
write('Enter the number of the line : ');
read(i);
write('Enter the number of the column : ');
read(j);
writeln('The value stored inn this cell is : ','[', matrix[i,j],']');
End;
// Start of main program
Begin
Head := Nil;
Repeat
writeln('*********** MENU ***********');
writeln('[1] fillFile');
writeln('[2] GetFromFile');
writeln('[3] SaveFromFile');
writeln('[4] SquareMatrix');
writeln('[5] ElementsOfSM');
writeln('[6] Element');
writeln('[7] WriteP');
writeln('[8] Content');
writeln('*********** End ***********');
write('Choose one : ');
read(N);
case N of
1 : fillFile();
2 : GetFromFile();
3 : SaveFromFile();
4 : SquareMatrix();
5 : ElementsOfSM();
6 : Element();
7 : WriteP();
8 : Content();
End;
Until (N<>1) and (N<>2) and (N<>3) and (N<>4) and (N<>5) and (N<>6) and (N<>7) and (N<>8) and (N<>9);
End.
The problem you describe is being caused by the known behaviour of the Read statement; basically, the second (and subsequent) times you call it, it returns immediately, without waiting for any keyboard input and without reading anything.
This happen because FPC is closely based on Object Pacal in the commercial Delphi development package, and in Delphi's case, this is the officially documented behaviour.
From the Delphi (v7) online help:
Delphi syntax:
Text files:
procedure Read( [ var F: Text; ] V1 [, V2,...,Vn ] );
Description
The Read procedure can be used in Delphi code in the following ways.
[...]
With a type string variable:
Read reads all characters up to, but not including, the next end-of-line
marker or until Eof(F) becomes true; it does not skip to the next line after reading. If the resulting string is longer than the maximum length of the string variable, it is truncated.
After the first Read, each subsequent Read sees the end-of-line marker and returns a zero-length string (emphasis added).
Use multiple Readln calls to read successive string values.
Fortunately, the solution is simple, use readln, instead of read, as in
readln(s);
Update Make sure you replace all instances of read by readln, as you have left a number of them unchanged, as #TomBrunberg has commented.
After that, run your code again and select 1 from the menu and you will find that fillFile executes, but the program terminates on the until ... line. And that's because it is a very bad idea to use the same global variable, in this case N for several different purposes throughout the program. So, you should edit your code further (and carefully) so that as far as possible it only uses global variables for global purposes. Turn all all the other variables into local variables, preferably with different names than the global ones. If after that you are still having problems, submit a new question focused on that.

All sums of a number

I need an algorithm to print all possible sums of a number (partitions).
For example: for 5 I want to print:
1+1+1+1+1
1+1+1+2
1+1+3
1+2+2
1+4
2+3
5
I am writing my code in Pascal. So far I have this:
Program Partition;
Var
pole :Array [0..100] of integer;
n :integer;
{functions and procedures}
function Minimum(a, b :integer): integer;
Begin
if (a > b) then Minimum := b
else Minimum := a;
End;
procedure Rozloz(cislo, i :integer);
Var
j, soucet :integer;
Begin
soucet := 0;
if (cislo = 0) then
begin
for j := i - 1 downto 1 do
begin
soucet := soucet + pole[j];
if (soucet <> n) then
Write(pole[j], '+')
else Write(pole[j]);
end;
soucet := 0;
Writeln()
end
else
begin
for j := 1 to Minimum(cislo, pole[i - 1]) do
begin
pole[i] := j;
Rozloz(cislo - j, i + 1);
end;
end;
End;
{functions and procedures}
{Main program}
Begin
Read(n);
pole[0] := 101;
Rozloz(n, 1);
Readln;
End.
It works good but instead of output I want I get this:
1+1+1+1+1
2+1+1+1
2+2+1
3+1+1
3+2
4+1
5
I can't figure out how to print it in right way. Thank you for help
EDIT: changing for j:=i-1 downto 1 to for j:=1 to i-1 solves one problem. But my output is still this: (1+1+1+1+1) (2+1+1+1) (2+2+1) (3+1+1) (3+2) (4+1) (5) but it should be: (1+1+1+1+1) (1+1+1+2) (1+1+3) (1+2+2) (1+4) (2+3) (5) Main problem is with the 5th and the 6th element. They should be in the opposite order.
I won't attempt Pascal, but here is pseudocode for a solution that prints things in the order that you want.
procedure print_partition(partition);
print "("
print partition.join("+")
print ") "
procedure finish_and_print_all_partitions(partition, i, n):
for j in (i..(n/2)):
partition.append(j)
finish_and_print_all_partitions(partition, j, n-j)
partition.pop()
partition.append(n)
print_partition(partition)
partition.pop()
procedure print_all_partitions(n):
finish_and_print_all_partitions([], 1, n)

Draw Pascal's triangle in PASCAL Programming like a diamond

How I can draw a Pascal's triangle in PASCAL Programming like a diamond from n number which we get that from input?
Edit:
This program I tried:
program Pascal_triangle;
var
i,j,n : integer;
A : Array[1..6,1..6] of Integer;
begin
n := 6;
for i:=1 to n do
begin
for j:=1 to i do
begin
if (j=1) or (i=j) then
begin
A[i,j]:=1;
end
else
begin
A[i,j] := A[i-1,j] + A[i-1,j-1];
end;
end;
end;
for i:=1 to n do
begin
Gotoxy(41-i,i);
for j:=1 to i do
write(A[i,j])
end;
readln;
end.
but I got an error on gotoxy line and I need it to be diamond.
Dec 31 '11 at 21:22: Thanks, I wrote this and works
program Pascal_triangle;
var d,c,y,x,n : integer;
begin
readln(n);
writeln;
for y:=0 to n do
begin
c:=1;
for d:=0 to n - y do
begin
write(' ');
end;
for x:=0 to y do
begin
write(c);
write(' ');
c := c * (y - x) DIV (x + 1);
end;
writeln;
end;
for y:=n-1 downto 0 do
begin
c:=1;
for d:=0 to n - y do
begin
write(' ');
end;
for x:=0 to y do
begin
write(c);
write(' ');
c := c * (y - x) DIV (x + 1);
end;
writeln;
end;
readln;
end.

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