Algorithm and Data structure (Lecture # 2)

Terminologies:

1) BIT:
           -BIT stands for "Binary digit".
           -A BIT is used to store a single Binary '0' or a single Binary '1'.
           -It is the smallest Binary '1';
           -It is the smallest piece of information that can not be further divided.

2) Nibble:
           -A combination of four related bits is called a NIBBLE.

 3) Byte:
           -A combination of two related nibbles OR eight related bits are called a BYTE.

 4) Character:
          -A byte is used to store a single character is a combination
                       OR
          -A character is a combination two NIBBLES or eight BITS.
          -A character is a small part of information and can be divided into BITS.
          -A character can be alphabetic (Aa--->zZ), digits (0-9) and any special symbol.

    ASCII:-
       8-bits (0-9)
        |  |
   Character

Total Character=2^8 = 256=>      0-255

5) Field:
           -A combination of related characters is called a field.
           -A field is usually meaningless, if it is treated all alone.
           -A field is commonly read from top to bottom.
           -A field can be
                                 For Example; st_id, st_name etc
     
6) Records:
           -A combination of same related field is called records.
           -Records are usually read from left to right
           -A records gives unit (complete) information about an entity e.g. student, fields in records is called degree of the RECORDS.

For Example:

Id	Name	Grade	Address
1234	Ali	A	Psh
2313	Akbar	A+	Isl
4568	Hamza	B	Pes
2545	Zohaib	B+	Lakki
7894	Hassan	A+	Kohat

         



7) File:
           -A File is a combination of related Records.
           -A File contains all the records of same type is:

             e.g; A student file can't contain faculty records.

           -Files are usually maintained by tables.

8) Block:
         -A Block is a combination of some Records in a file that can be treated as a logical unit.
         -There should be some commonalities between Records to create a Block.

    e.g. Block of  'A' grades.
     
     Dynamic set = Retrieved table
 
       -Number of Records in a Block is called Blocking factor.

     Query; Select *from student where address='Psh';






Operation on/for Data Structure:-

1) Creating:
            -Designing/Building a new empty data list or  bundle.

    e.g. int a;
           int a[3]

2) Inserting:
             -Entering a new item in an location of a data list
               a=5;
              for(i=5;i<= 1; i++)
               {
                 cin>>a;  
                 }

3) Traversing:
                -Visit each and every location of data list
                -While traversing no other operation is applied.
         
                    e.g.
                           for(i=0;i<=2;i++)
                           count<<a[i];
4) Deleting:
               -Removing/Erasing an element from a data list.
               -Deleting is usually performed by means writing.

          e.g. a=5;
                 a=6;
                 a=7;
           print a;
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