Cod sursa(job #365954)
Utilizator | Simoiu Robert SpiderMan | Data | 20 noiembrie 2009 15:48:56 |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | fpc | Status | done |
Runda | Arhiva de probleme | Marime | 0.49 kb |
program eratostene;
var f:array[1..1000000]of longint;
n,i,j,s:longint;
g:text;
begin
assign(g,'fractii.in');
reset(g);
readln(g,n);
close(g);
for i:=2 to n do
f[i]:=i-1;
for i:=1 to n div 2 do
begin
j:=2*i;
while j<=n do
begin
f[j]:=f[j]-f[i];
j:=j+i;
end;
end;
for i:=2 to n do
s:=s+f[i];
s := s*2 + 1;
assign(g,'fractii.out');
rewrite(g);
writeln(g,s);
close(g);
end.