Cod sursa(job #995685)
Utilizator | Data | 10 septembrie 2013 01:37:10 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.38 kb |
#include<fstream>
#include<bitset>
#define dim 100007
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int prim[dim];
int n,i,j;
bitset<dim>ok;
void ciur (){
prim[1]=2;
++prim[0];
for(i=3;i<=n;i=i+2){
if(ok[i]==0){
prim[++prim[0]]=i;
for(j=i;j<=n;j+=i)
ok[j]=1;
}
}
g<<prim[0];
}
int main () {
f>>n;
ciur();
return 0;
}