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вернуться в форумHelp !!How simple the (1068 Sum) is,but I'm wrong,Why? Var N,i,S,Sign:longint;
begin
readln(N);
if N>0 then Sign:=1 else Sign:=-1;
N:=Abs(N);
S:=Sign*(2+N)*(N-1) div 2 ;
writeln(S);
readln;
end. I'm fool,I misunderstood the problem. > Var N,i,S,Sign:longint;
>
> begin
> readln(N);
> if N>0 then Sign:=1 else Sign:=-1;
> N:=Abs(N);
> S:=Sign*(2+N)*(N-1) div 2 ;
> writeln(S);
> readln;
> end.
The Correct Program:
Var N,i,S,Sign:longint;
begin
readln(N);
if N>0 then Sign:=1 else begin N:=-N; Sign:=-1 end;
S:=sign*(1+N)*N div 2;
if sign<0 then S:=S+1;
writeln(S);
readln;
end. |
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