Cod sursa(job #339862)
Utilizator | Tertiuc Afanasie Scriam | Data | 11 august 2009 22:04:35 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.47 kb |
Program p1;
var k,n : longint;
f,g : text;
p : array[1..2000000] of boolean;
Procedure ciur;
var i,j : longint;
begin
fillchar(p,sizeof(p),true);
for i:=2 to n do
if p[i] then
begin
inc(k);
j:=2;
while i*j<=n do
begin
p[i*j]:=false;
inc(j);
end;
end;
end;
begin
assign(f,'ciur.in');
reset(f);
readln(f,n);
close(f);
k:=0;
ciur;
assign(g,'ciur.out');
rewrite(g);
writeln(g,k);
close(g);
end.