Brian Kernighan's technique to count set bits

Brian Kernighan's iterative technique to count set bits in an integer is described in the link below. Just a little help here to see how it works.

Let's start with an example.

Say for x = 9, you want to count number of set bits (9 = (1001) base 2)

Initialize a count variable to 0;

while (x > 0) {

Compute x - 1 = 8. 

Compute x = x & ( x - 1) 

increment count

}

Number of set bits = final value of "count" variable. Now, to see how it works, it is a good idea to rely on a method of back propagation. If you observe carefully, the stopping condition for the algorithm is when x = 0. It is good to understand when x becomes zero. x becomes zero during the iteration in which the value of x is a power of 2 which would also be when only one bit would be set in x.

http://www.geeksforgeeks.org/count-set-bits-in-an-integer/

WORKING!!! A decent hack for an unresolvable Gmail issue!

It has been long and I have something interesting to share here.

About 6 months back, one of my Gmail accounts became victimized by a series of spoofing attacks that continues till this day. For starters, spoofing attacks are not absolutely worrisome. Your account does not get compromised here. It happens when an unknown attacker starts spamming people with your email address in the from or sender section due to which you receive these great many email bounces everyday and also get your account blocked from further email compositions on that day. This is because Gmail has an outbound mail threshold of 500 per day after which any further outbound activity from your mailbox is temporarily blocked.

What is interesting about spoofing itself is that there is no known technique to remediate the attack once it is initiated on your account. As for me, I tried everything possible from filing a bug to reporting to Gmail and I finally understood that I would simply just have to let go. But, that was until my account itself got suspended by Gmail at which point I realized I had to either shut down my account or try to workaround it separately.

If you every find yourself in a similar predicament, here is a simple thing you can do to override account suspension. Gmail lets you set a default email address for all your outbound mails and if you can create a new sender account and have it configured to be the default mail address for all your outgoing mails, what you are in essence doing is let this account take over all unwanted outgoing spams that would have otherwise gone from your mailbox. Of course, this would not be a one time job and you would need to repeat this exercise when inevitably your designated sender account would get suspended too at some point. But, at least, you have something to begin with here.

I have been following the changes for about a week now and I am excited to announce that it has been working till this time :) :)