Wednesday, October 28, 2009

[DSA] posting of link in comment box

pls use HTML code

The following link is done with

<a href="http://URL" > the link < /a >

still figuring out how to post js in the comment box. as for entry, no problem encountered. If you have a solution to it, I did like to hear from you

Tuesday, October 20, 2009

[DSA] stun question Wk1

I came across this "game" when our department have a staff retreat at the Singapore flyer.
The objective of the game is to arrange staffs into 3 "E" characters.

Since this week our learning topics revolves around functions(), arithmetic evaluations, use of variables and proper programming methodology. I think it would be interesting to write a program to solve it. Anyway, during that period of time, access to a computer is a luxury. All equations have to be done on the paper. I manage to save this data in my memory and it is fresh still.

Attached is the screenshot of the piece of paper that illustrate the requirements.

Assume that the top and bottom horizontal bar is X, mid horizontal bar is (X-1) and the vertical bar is (X+1). Instinctively, this is a classic case where we can solve for X to the total number of staff and use it to form the "E". There is a possibility that there will be some staff remained, because we would want to maintain the uniformity of the 3 "E" characters.

3[(x-1)+2x+(x+1)] = total staff available.
which can further deduce to
12x = total staff available. => that is for forming 3 "E" characters.

Hence forming of 1 "E" character would be
4x = (1/3) staff available

The diagram below are not drawn to scale.

======== (x)
====== (x-1)
======== (x)

But how to translate the problem specs to code????????

we can use a divide and conquer approach to subdivide the problem into smaller portion.
Solving the algebra problem in the program might be redundant, since we have solve it on paper.

Some questions to ponder before start writing the code
a. what are the variables will be used.
b. do we need to use some form of data structure to store the temporary data?
c. what are the algorithms to calculate the X's, to display on the screen.

below are the sub-problem that need to be solve. drill down to further detail is not required.
1. Read in inputs from user for the number of staff available
2. Calculate how many will be left out from the E formation
3. calculate how many staff will form the top, mid and bottom horizontal bar
4. calculate how many staff will form the vertical bar
5. output to a screen

let the code and comments flow in!

Thursday, October 8, 2009

[DIY] Blinking LED bling belt buckle

Last Last week, attended one of my secondary school classmate's wedding. Btw, late Sept and early Oct I have already received 4x invites to wedding. More are in the pipeline..oh my goodnessssssss...........

Arghz, wedding reception is soOOooOoo boring. The food is usually not on par (mass produced), the alcohol is crazy (I'm in the brotherhood team, I'm used to blockade drinks targeting the groom.No drink driving please), lots of photo taking (I don't like to be the subject and I insisted to be photoshopped!!!! RAWRRR)

What totally grab my attention was my the first dish served, the cold platter. The lights are dimmed, Techno song was played (yeay!!!) and at the center of the dish there is this very "beng" blinking LED. It is in the shape of a dome, served in a cup of lightly coloured agar-agar (to give the light a medium to be illuminated). Quickly my I laid my paws on it before my bro daniel get to lay his! haha

Can' wait, I fished out my phone switch on the flash and tried to open the dome. But it is secured by screws! Well, I usually carry a handy tool set with me. No effort at trying to pry it open.

What drove me thinking was, how possible to pack 1 LED, some sort of controller/pic/MCU and battery cell small enough to fit into a dome shaped container at the size of a 20cents????

The content of the dome is just 1 LED and 2 button shaped battery (gives 3v). But, where is the controller???? Upon close inspection of the LED, i saw a tiny weeny black chip in the LED itself. That briefly explains the whole LED blinking sequences. My girl said I am "sua gu" (frog living in a well)...

well....I am pretty much exited with the "new" toy, open it up and find out that I can easily make 1 myself too without the hassle of wiring up a controller/MCU/pic and the considerations to make it small enough to be portable. The sample dome is in my office.

"Inspired" by this blinking LED, I was telling my trainees about this bling i going to make.
It is basically a belt buckle, complete with flashing LED.

Went Sim Lim Square (SLS) and Sim Lim Tower (SLT) last week for window shopping.

What?? Window shopping at SLS and SLT??? Not orchard ION, illuma? you gotta be kidding me!

Was hopping in and out of the shops in SLT looking for cool kit set and wares i can play with.
Chance upon this Flashing LED that cost 50cents each. They came complete default with flashing sequence, such that, there is no need to have a pic/MCU attached to the LEDs. Small is beautiful.

Initially, I only want to use 3v (button sized) to light up the LEDs, so all LEDs are wired in parallel circuit. Because there are too many branches and the current are divided at each branch of the circuit, it is not enough to drive the blinking LEDs. Normal LED are still OK. It Is in the circuit as a referencing point for the "beng-ness", lumens [brightness]. Actually, i only bought 10 of these. "LED not enough lar".

here I gave you my prototype belt buckle, 3v and 9v powered. Can spot the characters I am flashing?