Take BTech Tuition from the Best Tutors
Search in
Answered on 04/10/2020 Learn Computer science
CorpWin Technologies
Python is the most common coding language and is widely used. It is a favourite tool along being a flexible and open-sourced language. Its massive libraries like- Numpy, Pandas, SciPy, Keras, Pytorch, Tensorflow, Scikit-Learn and e.t.c which are used for data manipulation and are very easy to learn for a beginner or for professionals who want to know.
Data Science is the broad field in which you can learn about many concepts like- Python and R programming, Statistics, Probability and other topics of Mathematics, Machine Learning Algorithms, Techniques, Data Visualization tools- Big Data, SQL, NoSQL, Apache-Spark, MongoDB, PowerBI and e.t.c.
To learn data science and their other concepts, I would suggest you CorpWin technologies Programs. Corwin is one of the best training platforms to learn data science in depth. They provide the best course curriculum in which you will get all essential concepts of data science like- Python and its massive libraries concepts, Mathematics concepts, Techniques of ML and e.t.c.
read lessLesson Posted on 08/06/2020 Learn Computer science
Rohan
Many students have difficulty in understanding pointers. The best way to understand pointers is through memory representation.
Whenever we declare a variable, the computer allocates some amount of memory corresponding to this particular variable. Pointers are variables that store the address of another variable
Lesson Posted on 29/05/2018 Learn Computer science
Arijit Dutta
An Engineer Student loves teaching. Helps student to be in good position. Develop their skills. Go...
2Phase Lock in Distributed Database:
In this protocol, it is required that all the data items must be reached in a mutually independent manner, i.e. when one transaction is performing, then no other transaction should interrupt the process.
It requires both locks and unlocks being done in two phases:
But 2 PL won’t be able to solve other problems such as cascading rollback.
read lessTake BTech Tuition from the Best Tutors
Lesson Posted on 09/04/2018 Learn Computer science
Rahul Kasgar
More than three years of experience and can provide training in java(se), Android application development...
1. when we execute the java file, JVM is loaded into memory.
2. In JVM, first class loader starts which loads the class into memory, i.e. it divides the code intoRuntime Memory Area.
3. Runtime memory consists of:-
4. After the class loader, execution engine (JIT) runs which translate bytecode to machine-operable code.
read lessLesson Posted on 28/03/2018 Learn Computer science
Difference between System Software and Application Software
Ganesa Moorthi A
I worked in various institutes and engineering colleges as tutor about 8+ years and currently doing software...
The software is the virtual component of the computer through which we are doing our work.
The software is classified as System software and Application Software.
System Software provides the platform for loading application software. System software is the one who controls the hardware and helps users to do their work. It is the soul of the computer system. Once the device is designed, system software is loaded to make it live.
It is similar to humans, where once the body (hardware) is built, the body attains its system software in the name of soul.
Without system software, the hardware is a dead body. And also without hardware, the software is useless.
Application software is a set of programs or commands written to do a user-specific task. Different people use different types of application software. Based on the user requirements, we load our application software on the primary system software. It is like the development of our mind and knowledge based on the situation, schooling, surroundings for a human being.
So generally hardware is the body of the computer, while system software and application software are considered as soul and mind of computer respectively.
read lessLesson Posted on 22/03/2018 Learn Computer science
Ganesa Moorthi A
I worked in various institutes and engineering colleges as tutor about 8+ years and currently doing software...
In a computer, there are two major parts available namely hardware and software. both plays an important role in proper functioning of the computer.
Hardware are the touchable and physical parts of the computer. Hardware are visible to the user and it is visible even to a blind man. It is like the body of computer. Hardware provides the basic skeleton to load and work with software.
Software are nothing but the imaginary parts or virtual parts of the computer. Software is more complex and unable to understand easily. It is like mind or soul of the computer. It can't be touched or damaged. After finishing the design of hardware, Software is loaded into it.
When the hardware and software are working together, it becomes a computer. Without software, computer hardware is just a electronic board with connections. Without hardware, software cannot be used and can be stored only in CD or Pen Drive.
read lessTake BTech Tuition from the Best Tutors
Lesson Posted on 24/02/2018 Learn Computer science
Post - Fix Expression Evaluation Procedure
SR-IT Academy
SR - IT Academy is one of the leading tutorial point providing services like tutoring and computer training...
Algorithm:
1) Create a stack to store operands (or values).
2) Scan the given expression and do following for every scanned element.
a) If the element is a number, push it into the stack.
b) If the element is a operator, pop operands for the operator from stack. Evaluate the operator and push the result back to the stack
3) When the expression is ended, the number in the stack is the final answer.
read lessLesson Posted on 16/10/2017 Learn Computer science
Deepak
I am quite passionate about teaching physics and computer science. Linux OS and the whole system functions...
Lesson Posted on 08/08/2017 Learn Computer science
SR-IT Academy
SR - IT Academy is one of the leading tutorial point providing services like tutoring and computer training...
I. Hashing:
1. Hash Table Representation:
2. Hash Function:
Example:
Consider that we want place some employee records in the hash table The record of employee is placed with the help of key: employee ID. The employee ID is a 7 digit number for placing the record in the hash table. To place the record 7 digit number is converted into 3 digits by taking only last three digits of the key.
If the key is 496700 it can be stored at 0th position. The second key 8421002, the record of those key is placed at 2nd position in the array.
Hence the hash function will be:
H (key) = key%1000
Where key%1000 is a hash function and key obtained by hash function is called hash key.
The function H(key) is home bucket for the dictionary with pair whose value is key.
3. Types of Hashing Functions:
There are various types of hash functions that are used to place the record in the hash table:
i. Division or Modulus Method:
0 |
|
1 |
|
2 | 2 |
3 |
|
4 | 4 |
5 |
|
6 |
|
7 | 7 |
8 |
|
9 | 9 |
Example: If the record 54, 72, 89, 37 is placed in the hash table and if the table size is 10 then
h(key) = record % table size
4 = 54%10
2 = 72%10
9 = 89%10
7 = 37%10
ii. Mid Square:
In the mid square method, the key is squared and the middle or mid part of the result is used as the index.
If the key is a string, it has to be preprocessed to produce a number.
The formula for computing the hash key is:
h(key) = (key)2 =è and Result = middle digits of squared number or key
Example: Consider that if we want to place a record 3111 then:
(3111)2 = 9678321
For the hash table of size 1000
h(3111) = 783 (the middle 3 digits)
iii. Multiplicative hash function:
The given record is multiplied by some constant value. The formula for computing the hash key is-
h(key) = floor(p *(fractional part of key*A))
Where, p is an integer constant, and A is constant number.
Donald Knuth suggested to use constant A = 0.61803398987
Example: If key 107 and p = 50 then,
h(key) = floor(50*(107*0.61803398987))
= floor(3306.4818458045)
= 3306
At 3306 location in the hash table the record 107 will be placed.
iv. Digit Folding:
The key is divided into separate parts and using some simple operation these parts are combined to produce the hash key.
The formula for computing the hash key is:
h(key) = h(k1) +h(K2) +----
Where, h(k1), h(k2),… are separate parts used for computing key.
Example:
Consider a record 12365412 then it is divided into separate parts as 123, 654, 12 and these are added together
H(key) = 123+654+12
= 789
The record will be placed at location 789.
v. Digit Analysis:
The digit analysis is used in a situation when all the identifiers are known in advance. We first transform the identifiers into numbers using some radix, r. Then examine the digits of each identifier. Some digits having most skewed distributions are deleted. This deleting of digits is continued until the number of remaining digits is small enough to give an address in the range of the hash table. Then these digits are used to calculate the hash address.
4. Collisions In Hash Table:
The hash function is a function that returns the key value using which the record can be placed in the hash table. Thus this function helps us in placing the record in the hash table at appropriate position and due to this we can retrieve the record directly from that location. This function need to be designed very carefully and it should not return the same hash key address for two different records. This is an undesirable situation in hashing.
Definition: The situation in which the hash function returns the same hash key (home bucket) for more than one record is called collision and two same hash keys returned for different records is called synonym.
Similarly when there is no room for a new pair in the hash table then such a situation is called overflow. Sometimes when we handle collision it may lead to overflow conditions. Collision and overflow show the poor hash functions.
Index | Hash key |
0 |
|
1 | 131 |
2 |
|
3 | 43 |
4 | 44 |
5 |
|
6 | 36 |
7 | 57 |
8 | 78 |
9 | 19 |
For example,
Consider a hash function.
h(key) = recordkey%10 having the hash table size of 10
The record keys to be placed are:
131, 44, 43, 78, 19, 36, 57 and 77
Now if we try to place 77 in the hash table then we get the hash key to be 7 and at index 7 already the record key 57 is placed. This situation is called collision. From the index 7 if we look for next vacant position at subsequent indices 8,9 then we find that there is no room to place 77 in the hash table. This situation is called overflow.
5. Collision Resolution Techniques:
If collision occurs then it should be handled by applying some techniques. Such a technique is called collision handling technique.
There are two methods for detecting collisions and overflows in the hash table:
The two more difficult collision handling techniques are:
II. CHAINING:
In collision handling method chaining is a concept which introduces an additional field with data i.e. chain. A separate chain table is maintained for colliding data. When collision occurs then a linked list(chain) is maintained at the home bucket.
Example:
Consider the keys to be placed in their home buckets are:
131, 3, 4, 21, 61, 7, 97, 8, 9
Then we will apply a hash function as H(key) = key % D
Where, D is the size of table. The hash table will be:
Here D = 10
0
1
2
3
4
5
6
7
8
9
A chain is maintained for colliding elements. For instance 131 have a home bucket (key) 1. Similarly key 21 and 61 demand for home bucket 1. Hence a chain is maintained at index 1.
III. OPEN ADDRESSING :
i. LINEAR PROBING:
For example:
Consider that following keys are to be inserted in the hash table:
131, 4, 8, 7, 21, 5, 9, 29
Initially, we will put the following keys in the hash table.
We will use Division hash function. That means the keys are placed using the formula:
H(key) = key % table-size
H(key) = key % 10
For instance the element 131 can be placed at
H(key) = 131 % 10
= 1
Index 1 will be the home bucket for 131. Continuing in this fashion we will place 4, 8, 7.
Index | Hash key |
0 |
|
1 | 131 |
2 |
|
3 |
|
4 | 4 |
5 |
|
6 |
|
7 | read less Like 1 Comments Take BTech Tuition from the Best Tutors
Asked on 02/08/2016 Learn Computer science
what are the oppurtunities in abroad after doing phd in computer science?? Answer About UrbanProUrbanPro.com helps you to connect with the best BTech Tuition in India. Post Your Requirement today and get connected. You can also Learn x Ask a Question X Looking for BTech Tuition Classes?The best tutors for BTech Tuition Classes are on UrbanPro
![]() ![]() Take BTech Tuition with the Best TutorsThe best Tutors for BTech Tuition Classes are on UrbanPro Book a Free Demo |