Hi everyone,

I need some help in the following task:

I am writing a Pascal program that will

1). find the first 100 prime numbers and store them in an array.
2). give a choice to the user, who will choose which number base the prime numbers will be displayed in (I have to validate this entry, so only valid choices may be made). Then display the prime numbers in the requested base (base 10-decimal, base 2-binary, base 8-octal or base 16-hex).
3). quit the program when the option to quit is chosen.

The thing is that I managed to do only the first part of the program and I don't know how to continue the two other parts. If anyone is willing to help me, I would be grateful...Thank you in advance.

The first part of the program that I managed to do is the following:

Program Prime_Numbers;
uses crt;


Var
limit: longint;
p: array[1..52441] of boolean;
i, n : longint;
c:integer;



Begin
clrscr;


limit:= 52441; {search limit}


{assume all numbers are prime at first}


for n:=2 to limit do p[n]:= true;


{eliminate multiples of each pair}


for n:= 2 to Round(SQRT(limit)) do


IF p[n] Then


BEGIN
i := 0;


REPEAT
p[n * n + I * n] := false;


i := I + 1;
Until
n *n+i*n > limit;
End;


c:= 0;


for n:= 2 to limit Do


if p[n] And (c<100) Then
Begin
WriteLn(n);
c:=c+1;
end;


Readln;


End.

Edited 3 Years Ago by happygeek: fixed formatting

The second is easy. Pascal has built in libraries to convert numbers between bases, just use those.
The third is also easy, once you set up the structure of the program correctly.
At the moment you don't do anything to let the user choose what to do. Write that first.

Hi jwenting,

Thanks for the help. I managed to set up the main menu, however, I haven't understood what I should do in order to convert the prime numbers into binary, octal and hexadecimal. I tried to set up a new array and use the mod function but the program didn't work properly. Could you help me please because I'm just stuck in this part? Thank you in advance.

Hi everyone,

My assignment is due in two weeks time so any quick help would be greatly appreciated. Thanks in advance.

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