Popular Posts

Thursday, July 28, 2011

A Problem with Fenwick Tree

Problem:
You have an array like ar[]= {1,3,2,4,5,4,2}. You need to create
another array ar_low[] such that ar_low[i] = number of elements lower
than or equal to ar[i] in ar[i+1:n-1].
So the output of above should be {0,2,1,2,2,1,0}
Time complexity : O(nlogn)
use of extra space allowed.

Solution:
              Use Binary Indexed Tree.

Complexity: O(n log n)
Code:


1 comment:

  1. Can you please explain the logic behind the code.

    Thanks
    -B

    ReplyDelete