Двунаправленные списки

program spis;
uses crt;
type
pnode=^tnode;
tnode=record
val:integer;
pred,next:pnode;
end;
var
first,last,temp,temp2:pnode;
i,n,x,g:integer;
y:array[1..10] of integer;
 
procedure vvod(var first1,last1:pnode; xx:integer);
begin
if first1=nil then
begin
new(first1);
first1^.next:=nil;
first1^.pred:=nil;
last1:=first1;
end else
begin
new(last1^.next);
last1^.next^.pred:=last1;
last1:=last1^.next;
last1^.next:=nil;
end;
last1^.val:=xx;
end;
 
procedure fib(m:integer);
var i,j,k:integer;
temp,temp2:pnode;
begin
i:=1; j:=1; k:=1;
while k<m do
begin
k:=j+i;
i:=j;
j:=k;
end;
if k=m then
begin
 
while temp^.next<>nil do
begin
temp:=first;
if temp^.next^.val=m then begin
temp2:=temp^.next;
temp2^.pred:=temp^.pred;
temp^.next:=temp2^.next;
temp2^.next:=temp;
temp^.pred:=temp2;
end;
temp:=temp^.next;
end;
end;
end;
 
procedure vivod(first1:pnode);
begin
if first1=nil then
begin
writeln('Spisok pust');
exit;
end;
while first1<>nil do
begin
writeln(first1^.val);
first1:=first1^.next;
end;
end;
 
 
begin
clrscr;
write('n='); readln(n);
for i:=1 to n do
begin
write('x='); readln(x);
vvod(first,last,x);
y[i]:=x;
end;
for i:=1 to n do
begin
fib(y[i]);
end;
vivod(first);
readln;
end.