Cod sursa(job #1586533)
Utilizator | Vasilache Cosmin Teodor cosmin.vasilache95 | Data | 1 februarie 2016 12:54:07 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 90 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.53 kb |
#include <iostream>
#include <fstream>
#include <bitset>
#define MAX 2000000
using namespace std;
int main() {
fstream f("ciur.in",ios::in);
fstream g("ciur.out",ios::out);
int n,contor = 1;
f >> n;
bitset<MAX> nums;
for(int i=3;i<=n;i=i+2) {
if( nums.test(i) == true)
continue;
contor ++;
int k = 2*i;
while ( k<= n) {
nums.set(k,true);
k+= i;
}
}
g<< contor;
}