Queue

2) QUEUE USING ARRAY:

1) Procedure ( VAL )
[Description]

Step 1: [Check Queue is overflow or not]

If REAR >= SIZE – 1
Then
Write (‘Overflow…..’)
Return

Step 2: [Check it is first element or not]

If FRONT = = -1
Then
FRONT  0

Step 3: [Increment REAR pointer by 1]

REAR  REAR +1

Step 4: [Assign value]

Q [REAR]  VAL

Step 5: [Finished]

Return
--------------------------------------------------------------------------------------------
2) Function DELETE ( )
[Description]

Step 1: [Check Queue is empty or not]

If FRONT < 0
Then
Write (‘Queue Underflow……’)
Return -1

Step 2: [Delete an element]

VAL  Q [FRONT]

Step 3: [Queue Empty?]

If (FRONT = REAR)
Then
FRONT  REAR  -1
Else
FRONT  FRONT +1

Step 4: [Return the Deleted element]

Return VAL
----------------------------------------------------------------------------------------------
3) Procedure PRINT
[Description]

Step 1: [Check Queue is empty or not]

If FRONT < 0
Then
Write (‘Underflow…..’)
Return

Step 2: [Print the element of Queue]

Repeat For I = FRONT, FRONT + 1 …While I < = REAR
Write Q [I]

Step 3: [Finished]

Return


3) QUEUE USING LINK LIST :

4) Procedure INSERT( VAL )
[Description]

Step 1: [Allocate the memory location]

NEWNODE  NODE

Step 2: [Check memory is available or not]

If NEWNODE = NULL
Then
Write (‘Queue Overflow……)
Return

Step 3: [Insertion as a first NODE]

If REAR = NULL
Then
FRONT  REAR  NEWNODE
NEXT (REAR)  NULL
Return

Step 4: [Insertion as other NODE]

NEXT (REAR)  NEWNODE
REAR  NEWNODE
NEXT (REAR)  NULL
Return
--------------------------------------------------------------------------------------------
5) Function DELETE ( )
[Description]

Step 1: [Check Queue is empty or not]

If FRONT = NULL
Then
Write (‘Queue Underflow……’)
Return -1

Step 2: [Delete an element]

VAL  INFO (FRONT)

Step 3: [If needed reseat pointer]
If FRONT = REAR
Then
FRONT  REAR  NULL
Else
FRONT  NEXT (FRONT)

Step 4: [Return the Deleted element]

Return VAL
----------------------------------------------------------------------------------------------
6) Procedure PRINT
[Description]

Step 1: [Check Queue is empty or not]

If TEMP = NULL
Then
Write (‘Underflow…..’)
Return

Step 2: [Store FRONT into TEMP]

TEMP  FRONT

Step 3: [Print the element of Queue]

Repeat While TEMP # NULL
Write INFO (TEMP)
TEMP  NEXT (TEMP)

Step 4: [Finished]
Return