I got this error when trying to compile.
left side cannot be assign to, ./number 21,22 in pastebin
here is my code
Program urut;
Uses Wincrt;
Const N = 5;
data: Array [1..N] Of Integer = (2,4,5,3,1);
Var
j,k,temp : Integer;
Begin
Clrscr;
Writeln ('Data sebelum diurutkan');
For j:=1 To N Do
Begin
Writeln('data[' ,j, ']= ',data [j]);
End;
For j:=1 To N-1 Do
Begin
For k :=N Downto j+1 Do
Begin
If data[k] < data[k-1] Then
Begin
temp := data[k];
data[k] := data[k-1]; //left side cannot be assigned to
data[k-1] := temp; //left side cannot be assigned to
End;
End;
End;
Writeln;
Writeln ('Data setelah diurutkan ');
For j:=1 To N Do
Begin
Writeln ('data[' ,j, '] = ',data[j]);
End;
Writeln;
End.
sorry for uncorrectly pattern post
, thank you so much.
Like tom Tom Brunberg says, my array is const, it can't be changed. Therefore I need to remove that const.
So it should be
data: Array [1..5] Of Integer = (value);
without const, and put it under var with another variable
Related
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;
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.
My question is how can I read some number of integers that user enters on standard input, and place them in array.However I don't how many numbers user will enter and i can't ask him that? User enters numbers in one line.
Okay i have just one more answer i would like to add.Thanks all for your help this is code written based on suggestions.I added a line for writting array backwards just for you can see that it has readed well.
program backo;
var niz:array [1..100] of integer;
n, i:integer;
begin
i:=1;
writeln('enter elements of array');
read(niz[i]);
while not eoln do
begin
i:=i+1;
read(niz[i]);
end;
for n:=i downto 1 do
writeln(niz[n]);
end.
Ok, based on comments there is three ways demonstrated:
program readmultiint;
{$mode objfpc}{$H+}
uses
StrUtils;
const
CMaxValues = 3;
var
s: string;
darr: array of Integer;
sarr: array [0..CMaxValues-1] of Integer;
i, cnt: Integer;
begin
// Dynamic array using WordCount
Writeln('Enter values:');
Readln(s);
cnt := WordCount(s, StdWordDelims);
SetLength(darr, cnt); // Allocate room for values
for i := 0 to cnt - 1 do
Val(ExtractWord(i + 1, s, StdWordDelims), darr[i]);
for i in darr do
Writeln(i);
// Dynamic array usin EOLN
SetLength(darr, 0);
Writeln('Enter values:');
while not eoln do
begin
SetLength(darr, Length(darr) + 1); // Expand array for next value
Read(darr[High(darr)]);
end;
Readln; // Read <Enter> itself
for i in darr do
Writeln(i);
// Static array
cnt := 0;
Writeln('Enter values:');
while (not eoln) and (cnt < CMaxValues) do // Reads not more then CMaxValues values
begin
Read(sarr[cnt]);
Inc(cnt);
end;
Readln; // Read <Enter> itself
for i := 0 to cnt-1 do
Writeln(sarr[i]);
end.
Feel free to use one of them or provide your own :)
PS: Some readings:
Dynamic arrays
Val procedure
for-in loop
I am going to write a program that asks the user to enter items then choose the sorting type to sort them (bubble, inserion and selection).
After that I have to compare these types by time efficiency.
I wrote code for the first part, but I didn't know how to use a function in Pascal to write the second part (comparison).
This is what I have done:
Begin
writeln('How many Number you would like to sort:');
readln(size);
For m := 1 to size do
Begin
if m=1 then
begin
writeln('');
writeln('Input the first value: ');
readln(IntArray[m]);
end
else if m=size then
begin
writeln('Input the last value: ');
readln(IntArray[m]);
end
else
begin
writeln('Input the next value: ');
readln(IntArray[m]);
End;
End;
writeln('Values Before The Sort: ');
for m:=0 to size-1 do
writeln(IntArray[m+1]);
writeln();
begin
repeat
writeln(' ~*~...~*~ ~*~...~*~ ~*~...~*~ ~*~...~*~');
writeln('1. Insertion Sort.');
writeln('2. Bubble Sort.');
writeln('3. Selection Sort. ');
writeln('4. Exist ');
writeln('');
writeln('Enter your choice number: ');
readln(sort);
case sort of
1: begin {when choice = 1}
writeln('');
writeln(' The sorted numbers by Insertion sort are ~> ');
For i := 2 to size do
Begin
index := intarray[i];
j := i;
While ((j > 1) AND (intarray[j-1] > index)) do
Begin
intarray[j] := intarray[j-1];
j := j - 1;
End;
intarray[j] := index;
End;
for i:= 1 to size do
writeln(intarray[i]);
end;
2: begin {when choice = 2}
writeln('');
writeln(' The sorted numbers by bubble sort are ~> ');
For i := size-1 DownTo 1 do
For j := 2 to i do
If (intArray[j-1] > intarray[j]) then
Begin
temp := intarray[j-1];
intarray[j-1] := intarray[j];
intarray[j] := temp;
End;
for i:= 1 to size do
writeln(intarray[i]);
end;
3: begin {when choice = 3}
writeln('');
writeln(' The sorted numbers by selection sort are ~> ');
for i:=1 to size do
begin
j:= i ;
for index:= i +1 to size do
if intarray[index]<intarray[j] then
j:=index;
temp:=intarray[j];
intarray[j]:=intarray[i];
intarray[i]:=temp;
end;
for i:= 1 to size do
writeln(intarray[i]);
end;
4: begin
writeln('*~...~*~ Thank U For used Our Program We Hope You Enjoyed ~*~...~*~ ');
end;
end;
until sort = 4 ;
end;
end.
I hope that I will find the answer here...
I hope you know the TIME complexity of Bubble, Insertion and Selection sort.
If you know you can just compare like that
if (time_complexity_bub>time_complexity_ins)and(time_complexity_bub>time_complexity_sel) then writeln('Bubble Sort is the WORST !!!');
if (time_complexity_ins>time_complexity_bub)and(time_complexity_ins>time_complexity_sel) then writeln('Insertion Sort is the WORST !!!');
if (time_complexity_sel>time_complexity_ins)and(time_complexity_bub<time_complexity_sel) then writeln('Selection Sort is the WORST !!!');
If you have other questions you can ask me :D ...
Pascal supports >,>=,=,<= and < for comparison, but it seems you already know this:
if intarray[index]<intarray[j] then
So maybe you have to explain your question a bit clearer.
I think author is not sure how to measure time in Pascal.
I don't know what compiler you're using, but overall pattern is like:
var
startTime : TDateTime;
overallTime : TDateTime;
begin
startTime := SomeFunctionToGetCurrentTimeWithMicroseconds;
SomeLongOperation;
overalltime := SomeFunctionToGetCurrentTimeWithMicroseconds() - startTime;
end.
I write this program with pascal
which ask the user to enter two arrays and constant value which is K
the program muli the K with arrays .
and then save the answer in new array
and do some operation in new array
addition << work well
Subtraction << also work
BUT the problem in Multi << I am trying to ask the user to enter a new array and do Muti but still there is a problem.
ALSO
I want these operation repeated until the user press exit <<< I could not do this options because i am not perfect with pascal .
I would be grateful if you could help me
This is My Code
program BST6;
const maxN=100;maxM=100;
type mat=array[1..maxN,1..maxM]of integer;
var A,B,c:mat;
n,m,l,s,i,j,k:integer;
ch : char;
procedure readMat(var A:mat;var m,n:integer);
begin
for i:=1 to m do
for j:=1 to n do
begin
write('mat[',i,',',j,']=');
readln(A[i,j]);
end;
end;
procedure writeMat(A:mat;m,n:integer);
begin
for i:=1 to m do
begin
for j:=1 to n do
write(a[i,j]:4);
writeln;
end;
end;
function multK(A:mat;k:integer):mat;
begin
for i:=1 to n do
for j:=1 to m do
begin
B[i,j]:= K*A[i,j];
end;
multK:=B;
end;
function minus(A,B:mat):mat;
begin
for i:=1 to m do
for j:=1 to n do
C[i,j]:=A[i,j]-B[i,j];
minus:=C;
end;
function plus(A,B:mat):mat;
begin
for i:=1 to m do
for j:=1 to n do
C[i,j]:=A[i,j]+B[i,j];
plus:=C;
end;
function mult(A,B:mat;m,l,n:integer):mat;
begin
for i:=1 to m do
for j:=1 to n do
for k:=1 to l do
c[i,j]:=c[i,j]+A[i,k]*B[k,j];
mult:=C;
end;
begin
write('input m<=',maxM,'.. m=' );readln(m);
write('input n<=',maxN,'.. n=');readln(n);
readMat(A,m,n);
writeln('input the const K');readln(k);
B:=multK(A,K);
writeln('The matrix A : ');
writeMat(A,m,n);
writeln('The matrix B=K*A : ');
writeMat(B,m,n);
writeln('choose the operation + , - or * ');
readln(ch);
case ch of
'+' : c:=plus(A,B);
'-' : c:=minus(A,B);
'*' : begin
writeln('input m<=',maxM,'input l<=',maxN);readln(m,l);readMat(A,m,l);
writeln('input l<=',maxN);readln(n);readMat(B,l,n);
c:=mult(A,B,m,l,n);
end;
end;
writeMat(c,m,n);
readln;
end.
First of all having global one letter variables which collide with function parameters with the same name is insane.
Why does multK modify the global variable B as a sideeffect?
Why does minus modify the global variable C as a sideeffect?
Why global integers as for index variables?
And mult is even worse: It doesn't only modify C as a sideeffect, but it assumes C contains meaningful values beforehand. I think it needs to initialize C to all zeros beforehand.
My guess is some of your side effects interfere in strange ways. But I don't want to think it through. Refactor your code first. In particular learn how and when to use local variables.