Cod sursa(job #493404)
Utilizator | George Marcus PlayLikeNeverB4 | Data | 18 octombrie 2010 00:29:37 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 70 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
program ciurul_lui_eratostene;
const MAX=10000000;
var f,g:text; i,j,n,S:0..MAX; prim:array[1..MAX] of 0..1;
begin
Assign(f,'ciur.in'); Reset(f);
Assign(g,'ciur.out');Rewrite(g);
Read(f,n); Close(f);
i:=2;
While i<=n do
begin
prim[i]:=1;
inc(i);
end;
i:=2;
While i<=n do
begin
While (prim[i]=0)and(i<=n) do inc(i);
j:=2;
Repeat
prim[i*j]:=0;
inc(j);
Until i*j>n;
inc(i);
end;
S:=0;
For i:=2 to n do
If prim[i]=1 then inc(S);
Write(g,S); Close(g);
end.