rograff4.pas

This ar the basic programs that i did in highschool. From very simple to medium programs. From array

type stiva=array[1..50] of integer;
var st:stiva;
    a:array[1..50,1..50] of integer;
    n,m,k,x,y,i,j:integer;
    as,ev:boolean;
    f:text;
procedure init(var st:stiva;k:integer);
begin
st[k]:=0;
end;
procedure succesor(var st:stiva;k:integer;var as:boolean);
begin
if st[k]<n then begin
                inc(st[k]);
                as:=true;
                end
           else as:=false;
end;
procedure valid(st:stiva;k:integer;var ev:boolean);
var i:integer;
begin
ev:=true;
if (k>1) and (a[st[k-1],st[k]]=0) then ev:=false;

if ev then for i:=1 to k-1 do
   if st[i]=st[k] then ev:=false;
end;
function solutie(st:stiva;k:integer):boolean;
begin
solutie:=(st[k]=y);
end;
procedure tipar (st:stiva;k:integer);
var i:integer;
begin
for i:=1 to k do
   write(st[i], ' ');
writeln;
end;
begin
assign(f,'graf.txt');
reset(f);
readln(f,n,m,x,y);
for k:=1 to m do begin
                 readln(f,i,j);
                 a[i,j]:=1;
                 end;
close(f);
k:=1;
st[k]:=x;
k:=2;
init(st,k);
while k>1 do begin
             repeat
             succesor(st,k,as);
             if as then valid(st,k,ev);
             until (not as) or (as and ev);
             if as then if solutie(st,k) then tipar(st,k)
                                         else begin
                                              inc(k);
                                              init(st,k);
                                              end
                   else dec(k);
              end;
readln;
end.