纯数学题，搞了好久：
{ Author:wzx961008 Problem:UVa 10994-Simple Addition Verdict:Accepted Language:PASCAL Run Time:0.028s Submission Date:2011-01-30 15:00:23 } var p,q:longint; function f(n:int64):int64; var ans:int64; i:longint; begin if n<=0 then exit(0); ans:=0; while n<>0 do begin inc(ans,(n div 10)*45); for i:=(n div 10)*10+1 to n do inc(ans,i mod 10); n:=n div 10; end; exit(ans); end; begin while true do begin readln(p,q); if (p=-1)and(q=-1) then break; writeln(f(q)-f(p-1)); end; end.
