Cod sursa(job #929144)
Utilizator | Patrascu Eugen patrascu_eugen96 | Data | 26 martie 2013 21:16:55 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 10 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.57 kb |
program ciur;
type vector=array[1..2000005] of 0..1;
var prim:vector;
n,cnt,i,j:longint;
f,g:text;
begin
assign(f,'ciur.in');reset(f);
assign(g,'ciur.out');rewrite(g);
read(f,n);
cnt:=0;
j:=2;
for i:=2 to n do prim[i]:=1;
for i:=2 to n do if prim[i]=1 then while j<=n do begin
inc(cnt);
prim[j]:=0;
inc(j,i);
end;
writeln(g,cnt);
close(f);close(g);
end.