rograff7.pas

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

var a,b:array[1..50,1..50] of integer;
    k,x,y,c,m,n,i,j:integer;
    f:text;
    ok:boolean;
begin
assign(f,'graf.txt ');reset(f);
readln(f,n,m);
c:=0;
for k:=1 to m do begin
                 inc(c);
                 readln(f,x,y);
                 a[x,c]:=1;
                 a[y,c]:=-1;
                 end;
close(f);
for i:=1 to m do begin
                 for j:=1 to n do
                   if a[j,i]=1 then x:=j
                               else if a[j,i]=-1 then y:=j;
                 b[x,y]:=1;
                 end;
for i:=1 to n do
   for j:=1 to n do
      for k:=1 to n do
        if(i<>j)and(i<>k)and(j<>k) then
          if (b[i,k]=1) and (b[k,j]=1) then b[i,j]:=1;
ok:=true;
for i:=1 to n do
 for j:=1 to n do
  if (i<>j) and(b[i,j]=0)then ok:=false;
if ok then write('graf conex')
      else write('graful nu e conex');
readln;
end.