Variables automatically changes its value - freepascal

I'm doing this question with Pascal (Google Kick Start 2020 Round A - Workout) and I ran into a problem that doesn't make any sense at all. Here is a part of my program:
var N,K,i,max,max1 : longint;
M : array [1..100000] of longint;
A : array [1..99999] of longint;
begin
readln(N,K);
for i := 1 to N do
read(M[i]);
for i := 1 to N-1 do A[i] := M[i+1]-M[i];
max := 0;
for i := 1 to N-1 do
if A[i] >= max then
begin
max := A[i];
max1 := i;
end;
writeln('max = ',max); writeln('max1 = ',max1);
readln; readln;
end.
So first I type in all the input data which are:
5 6 and
9
10
20
26
30.
When I run the program, the value of max is 10 and the value of max1 is 2.
But when I change the way max gets its value and totally did nothing with max1, the program becomes like this:
uses crt;
var N,K,i,max,max1 : longint;
M : array [1..100000] of longint;
A : array [1..99999] of longint;
begin
readln(N,K);
for i := 1 to N do
read(M[i]);
for i := 1 to N-1 do A[i] := M[i+1]-M[i];
max := 0;
for i := 1 to N-1 do
if A[i] >= max then
begin
max := i;
max1 := i;
end;
writeln('max = ',max); writeln('max1 = ',max1);
readln; readln;
end.
I run the program, and suddenly both the values of max and max1 are 4. How can this happen? Should I delete Pascal?? By the way if you can't install Pascal for some reasons then go to this link:https://www.onlinegdb.com/, select Pascal language and paste my program. Thanks for helping me!

Related

can't extract value from Function

function takes for example rsi and from declared for me historical bar 1 to 12 finds me maximum value ( integer or '00,0') of rsi.
//#version=5
indicator("loop", shorttitle="loop")
len = input.int(14, title="RSI Length")
src = input.source(close, "RSI Source")
Rsi = ta.rsi(src, len)
plot(Rsi*10, "RSI", color=#673ed8)
hline(65,linestyle= hline.style_dashed , color=color.new(color.red, 0))
minF = 1, maxF = 12, RsiFunction = Rsi
ff_loopMax(RsiFunction,minF, maxF) =>
var float Max = na
var float MaxOdpCena = na
var int MaxNrBar = na
for i=minF to maxF
if i == minF
Max := RsiFunction[i]
//MaxOdpCena := high[i]
//MaxNrBar := i
else
//MaxOdpCena := Max > RsiFunction[i] ? MaxOdpCena : high[i]
//MaxNrBar := Max > RsiFunction[i] ? MaxNrBar : i
Max := math.max(Max,RsiFunction[i])
// I want Max result from function
plot(Max, "rsiMax", color=#b63253)
Result = ff_loopMax(Rsi,5,15)
The code extracted from function should work alone. But I can't cope with function.
A function in pine script return the value of the last expression. In your case, the last expression is Max, but you can't access this directly. You call the function, and set this return to a variable.
You should change the last two lines to:
Result = ff_loopMax(Rsi,5,15) // Result is now equal to Max
plot(Result, "rsiMax", color=#b63253)

Functions giving different result with same parameters

I use GMLib to work with Google maps and now I have come to a point where I am very confused.
I have the functions GetDistance and GetHeading to calculate the distance and compass direction between 2 markers on my map.
When I call them from my procedure GetHeadingDistance I get the result I expect (distance and direction is correct)- aSearchCallInfo is a class containing info that needs to be updated with the values.
Now I am trying to add a function that lets the user press the right mouse button on the map and the get info about that location.
But in this case I get very wrong results. As far as I can see of the results it uses GMMarker.Items[1].Position as source even when I know that it is GMMarker.Items[0].Position I send as parameter.
When I try to debug the functions by writing values to a textfile during calculation, I can see that it is the correct values it gets to work with at the correct position.
(GMMarker.Items[0].Position is the position of the user of the software)
Any ideas as what I could try to get this solved?
procedure TfrmQthMap.GMMapRightClick(Sender: TObject; LatLng: TLatLng; X, Y: Double);
var
MessageText: string;
LL: TLatLng;
Heading: double;
Distance: double;
Qra: string;
begin
if GMMarker.Count > 0 then
begin
LL := TLatLng.Create;
try
LL.Lat := LatLng.Lat;
LL.Lng := LatLng.Lng;
Heading := GetHeading(GMMarker.Items[0].Position, LL);
Distance := GetDistance(GMMarker.Items[0].Position, LL);
Qra := Maidenhead(LatLng.LngToStr, LatLng.LatToStr);
finally
FreeAndNil(LL);
end;
MessageText := 'Data for det sted du klikkede på: ' + sLineBreak + sLineBreak +
Format('Længdegrad: %s', [LatLng.LngToStr(Precision)]) + sLineBreak +
Format('Breddegrad: %s', [LatLng.LatToStr(Precision)]) + sLineBreak +
Format('Afstand: %6.1f km', [Distance]) + sLineBreak +
Format('Retning: %6.1f °', [Heading]) + sLineBreak +
Format('Lokator: %s', [Qra]);
ShowMessage(MessageText);
end;
end;
procedure TfrmQthMap.GetHeadingDistance(aSearchCallInfo: TCallInfo);
var
Heading: double;
Distance: double;
begin
if GMMarker.Count > 1 then
begin
Heading := GetHeading(GMMarker.Items[0].Position, GMMarker.Items[1].Position);
Distance := GetDistance(GMMarker.Items[0].Position, GMMarker.Items[1].Position);
barFooter.Panels[PanelDist].Text := Format('Afstand: %6.1f km', [Distance]);
barFooter.Panels[PanelDir].Text := Format('Retning: %6.1f°', [Heading]);
aSearchCallInfo.Distance := Format('%6.1f km', [Distance]);
aSearchCallInfo.Heading := Format('%6.1f °', [Heading]);
aSearchCallInfo.SaveToDatabase;
end;
end;
function TfrmQthMap.GetDistance(aOrigin, aDest: TLatLng): double;
var
Distance: double;
begin
Distance := TGeometry.ComputeDistanceBetween(GMMap, aOrigin, aDest);
Distance := Distance / 1000;
Result := Distance;
end;
function TfrmQthMap.GetHeading(aOrigin, aDest: TLatLng): double;
var
Heading: double;
begin
Heading := TGeometry.ComputeHeading(GMMap, aOrigin, aDest);
Heading := 180 + Heading;
Result := Heading;
end;

Find the combinations of 2 1's in a binary number

We have a binary number and we need to generate combination of 2 1's from the given number. If given such a combination of 2 1's we should be able to produce the next combination.
Example:-
Given vector : 10101111 Given combination : 10100000 output : 10001000
Given vector : 10101111 Given combination : 10001000 output : 10000100
Given vector : 10101111 Given combination : 10000010 output : 10000001
Given vector : 10101111 Given combination : 10000001 output : 00101000
Given vector : 10101111 Given combination : 00101000 output : 00100100
Edit:
Once the 2nd 1 reaches the last 1 in the given binary number, the 1st 1 is incremented(set to next '1' in the binary number and the 2nd '1' is made the '1' that comes after the 1st '1'(as in eg 4))
This is to be done in hardware so it should not be computationally complex. How can we design this module in VHDL.
Here is some asynchronous code that will do the job:
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
entity nex2ones is
Port ( vector : in STD_LOGIC_VECTOR (1 to 8);
combo1 : in STD_LOGIC_VECTOR (1 to 8);
combo2 : out STD_LOGIC_VECTOR (1 to 8);
error : out STD_LOGIC);
end nex2ones;
architecture Behavioral of nex2ones is
type int_array_8 is array (1 to 8) of integer range 0 to 8;
begin
process (vector,combo1)
variable ones_ixs : int_array_8;
variable first_combo1_ix : integer range 0 to 8 := 0;
variable second_combo1_ix: integer range 0 to 8 := 0;
variable first_combo1_k : integer range 0 to 9 := 0;
variable second_combo1_k : integer range 0 to 9 := 0;
variable k : integer range 1 to 9;
begin
ones_ixs := (others => 0); -- indices of 1s in vector
combo2 <= (others => '0');
k := 1;
first_combo1_ix := 0;
second_combo1_ix := 0;
first_combo1_k := 0; -- corresponding ptr to ones_ixs
second_combo1_k := 0;
error <= '0';
for j in 1 to 8 loop
if combo1(j) = '1' then
if first_combo1_ix = 0 then
first_combo1_ix := j;
first_combo1_k := k;
else
second_combo1_ix := j;
second_combo1_k := k;
end if;
end if;
if vector(j) = '1' then
ones_ixs(k) := j;
k := k + 1;
end if;
end loop;
if k > 1 then k := k - 1; end if; -- point to last nonzero index
if (first_combo1_ix = 0 or second_combo1_ix = 0)
--or (first_combo1_ix = ones_ixs(k-1) and second_combo1_ix = ones_ixs(k))
or (k < 2) then
error <= '1';
else -- no error proceed
if second_combo1_ix = ones_ixs(k) then -- can't slide 2nd anymore
if (second_combo1_k - first_combo1_k) > 1 then -- is 1st movable
combo2(ones_ixs(first_combo1_k + 1)) <= '1'; -- move 1st
if (second_combo1_k - first_combo1_k) > 2 then -- is 2nd movable
combo2(ones_ixs(first_combo1_k + 2)) <= '1'; -- move 2nd
else
combo2(ones_ixs(second_combo1_k)) <= '1'; -- leave 2nd be
end if;
else
error <= '1'; -- no mas
end if;
else
combo2(ones_ixs(first_combo1_k)) <= '1'; -- leave 1st be
combo2(ones_ixs(second_combo1_k + 1)) <= '1'; -- next
end if;
end if;
end process;
end Behavioral;
Testbench output:
ps vector combo1 combo2
error
0 00000000 00000000 00000000 1
100000 10101111 10100000 10001000 0
200000 10101111 10001000 10000100 0
300000 10101111 10000010 10000001 0
400000 10101111 10000001 00101000 0
500000 10101111 00101000 00100100 0
600000 10101111 00100100 00100010 0
700000 10101111 00000011 00000000 1
800000 11001110 00000110 00000000 1
900000 10001110 00001010 00000110 0
1000000 11001110 00001010 00000110 0

Traversing strings for multiple instances of substrings - freepascal or delphi

Platform : Lazarus 1.1, FreePascal 2.7.1, Win 7 32-bit.
I have a string value as follows:
FileName[12345][45678][6789].jpg
By default (assume this is default behaviour 0), my program currently pulls out the last set of numbers from the last pair of square brackets to the farthest right of the filename, i.e. 6789. It does so using this code:
if chkbxOverrideUniqueID.Checked then
IDOverrideValue := StrToInt(edtToggleValue.Text);
// User is happy to find the right most unique ID
if not chkbxOverrideUniqueID.Checked then
LastSquareBracket := RPos(']', strFileName);
PreceedingSquareBracket := RPosEx('[', strFileName, LastSquareBracket) + 1;
strFileID := AnsiMidStr(strFileName, PreceedingSquareBracket, LastSquareBracket - PreceedingSquareBracket)
else // User doesn't want to find the rightmost ID.
// and now I am stuck!
However, I have now added an option for the user to specify a non-default behaviour. e.g if they enter '1', that means "look for the first ID in from the farthest right ID". e.g. [45678], because [6789] is default behaviour 0, remember. If they enter 2, I want it to find [12345].
My question : How do I adapt the above code to achieve this, please?
The following code will return just the numeric value between brackets:
uses
StrUtils;
function GetNumber(const Text: string; Index: Integer): string;
var
I: Integer;
OpenPos: Integer;
ClosePos: Integer;
begin
Result := '';
ClosePos := Length(Text) + 1;
for I := 0 to Index do
begin
ClosePos := RPosEx(']', Text, ClosePos - 1);
if ClosePos = 0 then
Exit;
end;
OpenPos := RPosEx('[', Text, ClosePos - 1);
if OpenPos <> 0 then
Result := Copy(Text, OpenPos + 1, ClosePos - OpenPos - 1);
end;
If you'd like that value including those brackets, replace the last line with this:
Result := Copy(Text, OpenPos, ClosePos - OpenPos + 1);

Is there a Delphi standard function for escaping HTML?

I've got a report that's supposed to take a grid control and produce HTML output. One of the columns in the grid can display any of a number of values, or <Any>. When this gets output to HTML, of course, it ends up blank.
I could probably write up some routine to use StringReplace to turn that into <Any> so it would display this particular case correctly, but I figure there's probably one in the RTL somewhere that's already been tested and does it right. Anyone know where I could find it?
I am 99 % sure that such a function does not exist in the RTL (as of Delphi 2009). Of course - however - it is trivial to write such a function.
Update
HTTPUtil.HTMLEscape is what you are looking for:
function HTMLEscape(const Str: string): string;
I don't dare to publish the code here (copyright violation, probably), but the routine is very simple. It encodes "<", ">", "&", and """ to <, >, &, and ". It also replaces characters #92, #160..#255 to decimal codes, e.g. \.
This latter step is unnecessary if the file is UTF-8, and also illogical, because higher special characters, such as ∮ are left as they are, while lower special characters, such as ×, are encoded.
Update 2
In response to the answer by Stijn Sanders, I made a simple performance test.
program Project1;
{$APPTYPE CONSOLE}
uses
Windows, SysUtils;
var
t1, t2, t3, t4: Int64;
i: Integer;
str: string;
const
N = 100000;
function HTMLEncode(const Data: string): string;
var
i: Integer;
begin
result := '';
for i := 1 to length(Data) do
case Data[i] of
'<': result := result + '<';
'>': result := result + '>';
'&': result := result + '&';
'"': result := result + '"';
else
result := result + Data[i];
end;
end;
function HTMLEncode2(Data: string):string;
begin
Result:=
StringReplace(
StringReplace(
StringReplace(
StringReplace(
Data,
'&','&',[rfReplaceAll]),
'<','<',[rfReplaceAll]),
'>','>',[rfReplaceAll]),
'"','"',[rfReplaceAll]);
end;
begin
QueryPerformanceCounter(t1);
for i := 0 to N - 1 do
str := HTMLEncode('Testing. Is 3*4<3+4? Do you like "A & B"');
QueryPerformanceCounter(t2);
QueryPerformanceCounter(t3);
for i := 0 to N - 1 do
str := HTMLEncode2('Testing. Is 3*4<3+4? Do you like "A & B"');
QueryPerformanceCounter(t4);
Writeln(IntToStr(t2-t1));
Writeln(IntToStr(t4-t3));
Readln;
end.
The output is
532031
801969
It seems here is a small contest :) Here is a one more implementation:
function HTMLEncode3(const Data: string): string;
var
iPos, i: Integer;
procedure Encode(const AStr: String);
begin
Move(AStr[1], result[iPos], Length(AStr) * SizeOf(Char));
Inc(iPos, Length(AStr));
end;
begin
SetLength(result, Length(Data) * 6);
iPos := 1;
for i := 1 to length(Data) do
case Data[i] of
'<': Encode('<');
'>': Encode('>');
'&': Encode('&');
'"': Encode('"');
else
result[iPos] := Data[i];
Inc(iPos);
end;
SetLength(result, iPos - 1);
end;
Update 1: Updated initially provided incorrect code.
Update 2: And the times:
HTMLEncode : 2286508597
HTMLEncode2: 3577001647
HTMLEncode3: 361039770
I usually just use this code:
function HTMLEncode(Data:string):string;
begin
Result:=
StringReplace(
StringReplace(
StringReplace(
StringReplace(
StringReplace(
Data,
'&','&',[rfReplaceAll]),
'<','<',[rfReplaceAll]),
'>','>',[rfReplaceAll]),
'"','"',[rfReplaceAll]),
#13#10,'<br />'#13#10,[rfReplaceAll]);
end;
(copyright? it's open source)
Unit HTTPApp has a function called HTMLEncode. It has also other HTML/HTTP related functions.
I dont know in which delphi version it was introduced but, there is the System.NetEncoding unit which has:
TNetEncoding.HTML.Encode
TNetEncoding.HTML.Decode
functions. Read up here. You dont need external libraries anymore for that.
From unit Soap.HTTPUtil or simply HTTPUtil for older delphi versions, you can use
function HTMLEscape(const Str: string): string;
var
i: Integer;
begin
Result := '';
for i := Low(Str) to High(Str) do
begin
case Str[i] of
'<' : Result := Result + '<'; { Do not localize }
'>' : Result := Result + '>'; { Do not localize }
'&' : Result := Result + '&'; { Do not localize }
'"' : Result := Result + '"'; { Do not localize }
{$IFNDEF UNICODE}
#92, Char(160) .. #255 : Result := Result + '&#' + IntToStr(Ord(Str[ i ])) +';'; { Do not localize }
{$ELSE}
// NOTE: Not very efficient
#$0080..#$FFFF : Result := Result + '&#' + IntToStr(Ord(Str[ i ])) +';'; { Do not localize }
{$ENDIF}
else
Result := Result + Str[i];
end;
end;
end;
how about that way of replacing special characters:
function HtmlWeg(sS: String): String;
var
ix,cc: Integer;
sC, sR: String;
begin
result := sS;
ix := pos('\u00',sS);
while ix >0 do
begin
sc := copy(sS,ix+4,2) ;
cc := StrtoIntdef('$' +sC,32);
sR := '' + chr(cc);
sS := Stringreplace(sS, '\u00'+sC,sR,[rfreplaceall]) ;
ix := pos('\u00',sS);
end;
result := sS;
end;
My function combines the for-loop with a minimal reallocation of the string:
function HtmlEncode(const Value: string): string;
var
i: Integer;
begin
Result := Value;
i := 1;
while i <= Length(Result) do
begin
if Result[i] = '<' then
begin
Result[i] := '&';
Insert('lt;', Result, i + 1);
Inc(i, 4);
end
else if Result[i] = '>' then
begin
Result[i] := '&';
Insert('gt;', Result, i + 1);
Inc(i, 4);
end
else if Result[i] = '"' then
begin
Result[i] := '&';
Insert('quot;', Result, i + 1);
Inc(i, 6);
end
else if Result[i] = '&' then
begin
Insert('amp;', Result, i + 1);
Inc(i, 5);
end
else
Inc(i);
end;
end;
in delphi You have the function
THTMLEncoding.HTML.Encode