Cod sursa(job #1425029)
Utilizator | Andras Stefan Stefan. | Data | 26 aprilie 2015 13:49:55 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | fpc | Status | done |
Runda | Arhiva educationala | Marime | 0.78 kb |
program infoarena5;
var f,g:text;
contor,i:longint;
j,n:int64;
prim:array[1..2000000] of byte;
bufin, bufout:array[1.. 1 shl 17] of char;
begin
assign(f,'ciur.in'); reset(f);
assign(g,'ciur.out'); rewrite(g);
settextbuf(f, bufin); settextbuf(f, bufout);
readln(f,n); contor:=0;
for i:=2 to n do
if prim[i] = 0 then
begin
inc(contor);
j:=i+i;
while j <= n do
begin
prim[j]:=1;
j:=j+i;
end;
end;
writeln(g,contor);
close(f); close(g);
end.