Cod sursa(job #267919)
Utilizator | Udroiu Constantin Cristian cristian3991 | Data | 28 februarie 2009 15:07:14 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.63 kb |
var a:array[1..200000] of byte;
n,i,j,k:longint;
f,g:text;
begin
assign(f,'ciur.in');
reset(f);
readln(f,n);
fillchar(a,sizeof(a),1);
a[1]:=2;
k:=0;
for i:=2 to n do
begin
if a[i]=1 then begin j:=i;
k:=k+1;
while j<=n do
begin
j:=j+i;
a[j]:=2;
end;
end;
end;
assign(g,'ciur.out');
rewrite(g);
writeln(g,k);
close(f);
close(g);
end.