Yikes!! A zombie table in Hbase.

In the process of playing around with HBase through the shell, I suddenly experienced a strange error.   When  I tried to create the table, I  got an error that the table exists .  When trying to delete, it complained that the table never existed.

 I later realized that Zookeeper had an entry of the table . Below are the steps I followed to delete the entry   from zookeper. 

 Start Zookeeper client . To do that, run  hbase zkcli
From the prompt, i ran ls /hbase/table to see the list of tables 
To delete the zombie table,  I ran  delete /hbase/table/{tablename}

Removing duplicate elements in a integer array

I came across an interview puzzle the other day where i was asked to write a program that removes duplicate entries in an integer array.

The pseudocode for solving this using a bit map data structure is below
a) for I : 1 to N do
bit[i] := 0;
b) for each integer I in input data do
bit[I] := 1;
c) for I: 1 to N do
if(bit[i] == 1) then
write to output int array.


import java.util.BitSet;
class RemoveDups {
public static void main(String[] args) {
// given input
int[] input = new int[] { 1, 4, 4, 2, 6, 18 };
// iterate through the array and set the bit to true for the corresponding integer
BitSet bset = new BitSet();
for (int i = 0; i < input.length; i++) {
bset.set(input[i]); // Sets the bit at the specified index to true
}
// iterate through the bset
int[] output = new int[input.length];
int count = 0;
for (int i = 0; i < bset.length(); i++) {
if (bset.get(i)) {
output[count++] = i;
}
}
}
}
Finally , the output array holds the list of distinct integers.