Thursday, October 18, 2012

Disable/Enable USB

Make USB storage devices totally useless without your permission.

I am going to show you how you can make USB storage devices totally useless without your permission.

To block all the storage device in your Windows, run registry editor by typing regedit in RUN command.In the registry editor, at left side navigation pane, navigate to following location:

HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Services > USBSTOR

Now at the right side double click on START.

















To block USB storage Medias, change the value data to 4.















If you want to unblock USB storage  change the value data to 3.



Tuesday, October 16, 2012

Remote Session

Kill Remote Session using QWINSTA and RWINSTA

If you need to terminal service to a remote windows server, but cant because no sessions are available, you can use QWINSTA and RWINSTA to query then kill offending sessions so then you can get to the server.

First, use QWINSTA to query the sessions:
From a command prompt enter:
qwinsta /server:servername
Example:







In the above example I have shown “nameofserver” instead of the actual server name.
Note the ID of the session that you want to kill. In this case, we will kill session ID 2 (pdouglas)

To kill the session, use RWINSTA:
From the command prompt enter:
rwinsta ID /server:servername


Sunday, October 14, 2012

Facebook’s Hackers Cup



Russia’s Roman Andreev wins Facebook’s Hackers Cup

 Facebook’s 2nd annual Hacker Cup competition, held at the company’s headquarters in Menlo Park, California, witnessed 25 of the world’s best hackers gather for an intense competition.The contest is an annual algorithmic programming contest that Facebook makes open to engineers from anywhere in the world.The 25 finalists were flown to Facebook’s headquarters for the final. Of the 25 top coders, all were male, and included students, independent coders, and professionals.The 25 finalists were given three hours to solve 3 problems, with the winner being the first to correctly finish a problem. The winner is awarded  the title of “hacker world champion,” along with a prize of $5,000. The second place prize is $2,000, third place is awared $1,000, and the remaining 22 finalists each received $100.

Roman Andreev of Russia took top prize by correctly completing a problem in 1 hour and 4 minutes, one minute ahead of the second place winner. Andreev received an unusually-designed and heavy trophy made of cement, along with a check for $5,000.



1st place: Roman Andreev from Russia, completed one problem correctly in 1 hr 4 min
2nd place: Tomek Czajka from the US, completed one problem correctly in 1 hr 5 min
3rd place: Tiancheng Lou from China, completed one problem correctly in 1 hr 44 min

Facebook Hacker cup Problem solved






Party Time

You're throwing a party for your friends, but since your friends may not all know each other, you're afraid a few of them may not enjoy your party. So to avoid this situation, you decide that you'll also invite some friends of your friends. But who should you invite to throw a great party?

Luckily, you are in possession of data about all the friendships of your friends and their friends. In graph theory terminology, you have a subset G of the social graph, whose vertices correspond to your friends and their friends (excluding yourself), and edges in this graph denote mutual friendships. Furthermore, you have managed to obtain exact estimates of how much food each person in G will consume during the party if he were to be invited.

You want to choose a set of guests from G. This set of guests should include all your friends, and the subgraph of G formed by the guests must be connected. You believe that this will ensure that all of your friends will enjoy your party since any two of them will have something to talk about...

In order to save money, you want to pick the set of guests so that the total amount of food needed is as small as possible. If there are several ways of doing this, you prefer one with the fewest number of guests.

The people/vertices in your subset G of the social graph are numbered from 0 to N - 1. Also, for convenience your friends are numbered from 0 to F - 1, where F is the number of your friends that you want to invite. You may also assume that G is connected. Note again that you are not yourself represented in G.

Input
The first line of the input consists of a single number T, the number of test cases. Each test case starts with a line containing three integers N, the number of nodes in G, F, the number of friends, and M, the number of edges in G. This is followed by M lines each containing two integers. The ith of these lines will contain two distinct integers u and v which indicates a mutual friendship between person u and person v. After this follows a single line containing N space-separated integers with the ith representing the amount of food consumed by person i.

Output
Output T lines, with the answer to each test case on a single line by itself. Each line should contain two numbers, the first being the minimum total quantity of food consumed at a party satisfying the given criteria and the second the minimum number of people you can have at such a party.

Constraints
T = 50
1 ≤ F ≤ 11
F ≤ N-1
2 ≤ N ≤ 250
N-1 ≤ M ≤ N * (N - 1) / 2
G is connected, and contains no self-loops or duplicate edges.
For each person, the amount of food consumed is an integer between 0 and 1000, both inclusive.

Thursday, October 11, 2012

Top 10 Technology Concepts

 

10. Windows Registry

The Windows Registry is a hierarchical database that stores the configuration settings of the operating system as well as application software that are installed in your PC. It is simply a database that stores your computer hardware, software, user settings, security and property settings for folders and programs. It is an important part place in the Windows OS, where most of the apps are stored.

9. SSL Encryption/HTTPs

HTTPs stands for Hypertext Transfer Protocol Secure and is a URL scheme that is in sync with the normal HTTP connections, but has an additional signal that secures the browser with an encryption layer of SSL/LS to protect the traffic.
It is a combination of HTTP and SSL/TLS protocols to provide encrypted communication and secure identification of a web server. The SSL encryptions are usually used for payment transactions or sensitive corporate information that passes through the World Wide Web.

8. Network Neutrality

As the name suggests, Net Neutrality is all about creating a neutral Internet. It is also known as Internet neutrality or Network Neutrality. According to this concept, Internet traffic should be treated equally. The term also supports the view that Internet should be an open platform, just like any other home utility, as it has now become a necessary part of our daily lives.
Net Neutrality believes in no restrictions by the Internet Service Providers (ISPs) and governments on sites, content and the types of commodities that are attached to the modes of communication.

7. 4G

4G is the fourth generation of wireless cellular standards in telecommunications. The peak speed requirements for 3G service is 100 Mbit/s for high mobility communication and 1Gbit/s for low mobility communication.A 4G system provides a secure mobile broadband solution to smartphones, wireless modems and laptops. Internet access, IP telephony, gaming services and multimedia streaming services are all provided by the 4G system. Technologies such as WiMAX and LTE are 4G technologies.

6. Lossless and Lossy Music

Usually, audio compression comes in two forms-lossless compression and lossy compression. In the lossless audio format, the audio files retain every bit of information that is found in the original so that nothing is lost.
The lossy format is the audio compression that loses some of the information found in the original, especially when you are compressing the file to make it smaller. The MP3 format is the lossy compression format. Here the very high and the very low frequencies are often skipped during compression.

5. 32-Bit and 64-Bit Operating Systems

The terms 32-bit and 64-bit imply the way a computer’s CPU handles information. The 64-bit version of the operating system can handle huge amounts of RAM and more effectively than the 32-bit operating system. For the 64-bit version to be installed, your computer needs a processor that is capable of running a 64-bit version of the Windows OS. The main advantage of the 64-bit is that it is more responsive when you are running several programs at the same time.

4. Android Task Killers

Android Task killers were earlier considered very useful tools. They could improve your phone’s performance and boost battery life. However, they are no longer used, as they do more harm than good to your Android phones.
A task killer is an app from which you can force other apps to quit, providing more space on your Android OS for other apps to work speedily. It is advisable that you don’t use them unless you know perfectly well how they function.

3. Proper Windows maintenance

To keep your computer running smoothly you should know how to maintain, restore and have a back up of your registry. Improper entries in the registry can destroy the whole Windows operating system.
For proper Windows maintenance, see that you have a back up of your registry before editing it. Then you need to clean up your registry as it may be filled with cluttered unwanted programs. The other aspect of Windows maintenance is to fix a damaged registry as this will restore something that has been inadvertently damaged.

2. Spyware, Viruses, Trojans, Worms and other Malware

Viruses, trojans and worms are all a sort of malicious software programs that are designed to disrupt your computer operations or gather information through unauthorized access to system resources. There are thousands of viruses, Trojans, worms, bots and root kits all stalking out there waiting to infest your computer. It therefore makes sense to have a very good antivirus software package installed to combat with this menace.

1. Wi-Fi and Wireless Internet

Wi-Fi is a wireless communication standard that is used between computer devices to share resources and data. The Wi-Fi signals cannot travel a long distance and are therefore used for Local Area networks.
To set up a Wi-Fi network, the main computer acts as a server with  interface card. This card features a small antenna that receives and broadcast WiFi signals. A high speed modem assists the direction of the traffic with the help of a router and a switch, to integrate wireless internet into the WiFi LAN. Now any computer in the vicinity can make use of the WiFi signals and connect to the Internet using the WiFi Network interface card. Smartphones, Mobiles, PDAs and laptops have a built-in Wi-Fi ability that enables them to surf the Internet, access or transfer data with speed and efficiency.
These are some of the technology concepts that one should know as they may come handy at some time or the other. With the vast trove of technology terms, sometimes a lifetime may not be enough to learn all of them.