8.5.java

//
//  8.5.java
//  Chapter8
//
//  Created by Apollo Zhu on 8/11/16.
//  Copyright © 2015-2016 WWITDC. All rights reserved.
//

   public static boolean[] sieve(int n){
      boolean[] result = new boolean[n];
      for (int i=2;i<n;i++)
         result[i] = true;
      for (int number=2;number<=(int)Math.sqrt(n);number++){
         if (result[number] == true){
            for (int indexInSeries = number*number;indexInSeries < n;indexInSeries += number){
               result[indexInSeries] = false;
            }
         }
      }
      return result;
   }