Cod sursa(job #289717)
Utilizator | Dan H Alexandru danalex97 | Data | 26 martie 2009 22:14:06 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
program Ciur;
var n,i,j,k,l:longint;
a:array[1..2000000] of byte;
fl:text;
begin
assign(fl,'ciur.in');
reset(fl);
readln(fl,n);
close(fl);
for i:=1 to n do
a[i]:=1;
a[1]:=0;
k:=0;
for i:=2 to n do
if (a[i]=1) then
begin
j:=2*i;
inc(k);
while j<=n do
begin
a[j]:=0;
inc(j,i);
end;
end;
assign(fl,'ciur.out');
rewrite(fl);
writeln(fl,k);
close(fl);
end.