Changed to prevent abuse*

Question

1.07/5 (9 votes)

See more:

Python

def asallar(limit):
   limitn = limit+1
   asal_degil = [False] * limitn
   asal_listesi = []
 
   for i in range(2, limitn):
       if asal_degil[i]:
           continue
       for f in xrange(i*2, limitn, i):
           asal_degil[f] = True
       asal_listesi.append(i)
 
   return asal_listesi

Python

a = asallar(1000000)
print a[9999]

Python

timeit asallar(1000000)

What I have tried:

Changed title in hopes trolls may avoid this post

Posted 23-Apr-15 1:58am

eboolean

Updated 2-Oct-21 5:44am

jeron1

v3

Add a Solution

2 solutions

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CPallini · Answer 1 · 2018-12-10T10:31:00

C++

#include <iostream>
using namespace std;

vector <int>  asallar(size_t limit)
{
  vector <bool> nov(limit+1, false);
  vector <int> result;
  for (size_t i=2; i<=limit; ++i)
  {
    if ( nov[i] ) continue;
    for (size_t f = i*2; f<=limit; f+=i)
    {
      nov[f] = true;
    }
    result.push_back(i);
  }
  return result;
}

int main()
{
  auto v = asallar(1000000);
}

Timing:

Python program: about 300 ms
C++ program:    about 100 ms

Please note: if a vector<int> (instead of a vector<bool>) is used in the C++ program, then the execution speed is doubled.

BacchusBeale · Answer 2 · 2015-04-23T02:28:00

For C, something like in the comments:

C++

def asallar(limit): \\ void asallar(int limit, int* asal_listesi){
   limitn = limit+1 \\ int limitn =limit+1;
   asal_degil = [False] * limitn \\ int *asal_degil = malloc(...)
   asal_listesi = [] \\ vector asal_listesi; 
 
   for i in range(2, limitn): \\ for(int i=2; i<limitn;>       if asal_degil[i]: \\ if(asal_degil[i])
           continue       \\ continue;
       for f in xrange(i*2, limitn, i): \\ etc
           asal_degil[f] = True
       asal_listesi.append(i)
 
   return asal_listesi

Changed to prevent abuse*

2 solutions

Solution 11

Solution 1

Add your solution here

Preview 0

****Changed to prevent abuse*****

2 solutions

Solution 11

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us

Changed to prevent abuse*