Databases
StackOverflow2013
Postsdbo
POHow to search for a range of values using binary search?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to search for a range of values using binary search?
    primarykey
    data
    text
    <p>I am trying to write a program that will take an <em>ArrayList</em> of sorted integers, and there will be a binary search method where you specify the range and the values that you want to be returned from the <em>ArrayList</em>.</p> <pre><code>import java.util.ArrayList; public class ArraySearch { ArrayList&lt;Integer&gt; myArrayList = new ArrayList&lt;Integer&gt;(); static ArrayList&lt;Integer&gt; range = new ArrayList&lt;Integer&gt;(); public static ArrayList&lt;Integer&gt; binarySearch(ArrayList&lt;Integer&gt; arrayList, int min, int max, int first, int last) throws NotFoundException { if(first &gt; last) { throw new NotFoundException("Elements not found."); } else { int middle = (first + last) /2; int mid_number = arrayList.get(middle); if(mid_number &gt;= min &amp;&amp; mid_number &lt;= max) { range.add(middle); } if(mid_number &lt;= min) { if(mid_number == min) { range.add(arrayList.get(middle)); return binarySearch(arrayList, min, max, first, middle-1); } return binarySearch(arrayList, min, max, first, middle-1); } else { if(mid_number == max) { range.add(arrayList.get(middle)); return binarySearch(arrayList, min, max, middle+1,last); } return binarySearch(arrayList, min, max, middle+1,last); } } } public static void main (String [] args) throws NotFoundException { ArrayList&lt;Integer&gt; a = new ArrayList&lt;Integer&gt;(); a.add(0); a.add(1); a.add(2); a.add(3); a.add(6); a.add(7); a.add(7); a.add(10); a.add(10); a.add(10); binarySearch(a, 3, 7, 0, 9); } </code></pre> <p>}</p> <p>Could I please get some help?<br> I have no idea what the base case condition should be that should return the <em>ArrayList</em> range. And I think I might have got the logic in the binary search method wrong.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USinformatik01
    1. UStenkii
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to search for a range of values using binary search?
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. COYou can binary search the minimum value of the range and then maximum and return everything in between.
      singulars
      1. POHow to search for a range of values using binary search?
      1. USBula
    2. COYou might as well just find the minimum and then iterate linearly up from there until you go over the maximum. It will take linear time to build up the return value anyway.
      singulars
      1. POHow to search for a range of values using binary search?
      1. USjacobm
    3. COBula could you elaborate more on how to do this because I am not sure
      singulars
      1. POHow to search for a range of values using binary search?
      1. UStenkii
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload