Here is testgen, I used to accept this problem, maybe it will help you:
program gen;

{$APPTYPE CONSOLE}
const n=1000;
const m=100000;
var a:array [1..n] of Integer;
    was:array [1..n,1..n] of Boolean;
    i,buf,buf1:Integer;
begin
 randomize;
 assignfile(output,'in.txt');rewrite(output);
 fillchar(was,sizeof(was),0);
 for i:=1 to n do
  was[i,i]:=true;
 for i:=1 to n do
  a[i]:=random(10000)-random(10000);
 writeln(n,' ',m);
 for i:=1 to m do
 begin
  repeat
  buf:=random(n)+1;
  buf1:=random(n)+1;
  until was[buf,buf1]=false;
  was[buf,buf1]:=true;
  was[buf1,buf]:=true;
{  if i=60000 then
  writeln(buf,' ',buf1,' ',a[buf]+a[buf1]+1) else}
  writeln(buf,' ',buf1,' ',a[buf]+a[buf1]);
 end;
 writeln;
 for i:=1 to n do
  writeln(a[i]);
 closefile(output);
end.