Cod sursa(job #2376110)
Utilizator | Data | 8 martie 2019 13:41:09 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <iostream>
#include <fstream>
using namespace std;
int main(){
ifstream f("ciur.in");
ofstream g("ciur.out");
int i,j,n,cnt=0;
char prim[2000005];
f>>n;
for(i=1;i<=n;i++) prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i])
{cnt++;
for(j=i+i;j<=n;j+=i) prim[j]=0;}
g<<cnt;
return 0;}