Things To Do...

I recently attended a Spring training by SpringSource. While learning the framework and admiring its features, it prick me that there is a LOT that I don't know and have to gather.

So, after a long time I'm starting this post, that I anticipate to update regularly with things I want to do, things I want to learn and things I want to talk about.

Expect one blog title for each entry in this list. So, here I go :

1. P1: Spring - an E2E tutorial - put to use all the learning from the training into a live example.
2. P2: OSGi - post an article listing resources I read to understand OSGi. Maybe with a few self comments
3. P?: Groovy - I really loved the way Groovy scripts helped code Java applications quickly. I'm going to try them out
   
4. P?: Grails - Another quick build of a web application. I'm going to try this out too.
5. P?: Castor - Data binding framework : http://www.castor.org/
6. P?: JBoss Seam
7. P?: Spring Roo : http://en.wikipedia.org/wiki/Spring_Roo
8. P2: Why should one refrain from using Stubs and prefer using XPath for Web service implementation (server side)
9. P2: Code-first VS contract-first approach for webservices
10. P?: The JSF standard
11. P2: Distributed transactions - an interesting concepts / field. How about starting here : Distributed transactions in Spring, with and without XA
12. P2: Java Persistence API : https://glassfish.dev.java.net/downloads/persistence/JavaPersistence.html
13. P?: JDO : http://java.sun.com/jdo/
14. P2: JSR-250 Common Annotation
15. P1: Introduction to Algorithms @ MIT Open Courseware - http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Computer-Science/6-046JFall-2005/CourseHome/index.htm
16. P?: A course / reading on OOAD, Systems Analysis, Design
17. P?: Machine Learning Modeling Algo : Linear CRF - What? How?
    

.... (To be continued...)

Walk the bridge, in pairs as fast a possible

There are 4 women who want to cross a bridge. They all begin on the same side. There is one flashlight. A maximum of two people can cross at one time. It is night. Any party who crosses, either 1 or 2 people, must have the flashlight with them. The flashlight must be walked back and forth, it cannot be thrown, etc. Each woman walks at a different speed. A pair must walk together at the rate of the slower woman's pace.
Woman 1: 1 minute to cross
Woman 2: 2 minutes to cross
Woman 3: 5 minutes to cross
Woman 4: 10 minutes to cross

For example if Woman 1 and Woman 4 walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Woman 4 then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission.

Find jar with the contaminated pills

You have 4 jars of pills. Each pill is a certain weight, except for contaminated pills contained in one jar, where each pill is weight + 1. How could you tell which jar had the contaminated pills in just one measurement?

Source : http://www.sellsbrothers.com/fun/msiview/default.aspx?content=question.htm

Algorithms from "100 Interview Questions for Software Developers" : Part 3

Find repeating element in array

I felt this  question deserves a post of its own. So here it is :

 Q5. In an array from 1 to n, one number is present twice. How to do you determine which one?

There are multiple answers - all correct. We would, obviously, aim for the optimized one - benchmark parameters being time & space complexity

Source : Algorithms from 100 Interview Questions for Software Developers

Algorithms from "100 Interview Questions for Software Developers" : Part 2

Q3. How do you find the middle item in a link list?
Q4. How would you write a function to reverse a string? Can you do it without a temporary string?

Source : Algorithms from 100 Interview Questions for Software Developers

Find the bulb for the switch

There is a room with a door (closed) and three light bulbs. Outside the room there are three switches, connected to the bulbs. You may manipulate the switches as you wish, but once you open the door you can't change them. Identify each switch with its bulb.

Source : My brother & http://www.sellsbrothers.com/fun/msiview/default.aspx?content=question.htm

Find direction of rotation

Imagine a disk spinning like a record player turn table. Half of the disk is black and the other is white. Assume you have an unlimited number of color sensors. How many sensors would you have to place around the disk to determine the direction the disk is spinning? Where would they be placed?

Source : http://www.sellsbrothers.com/fun/msiview/default.aspx?content=question.htm