Ordered sequence: Difference between revisions

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'''Input:''' A key <math>K \in \kappa</math>.
'''Input:''' A key <math>K \in \kappa</math>.


'''Output:''' A Boolean value, which is '''''true''''' if, and only if, <math>K</math> is currently stored in the sequence.
'''Output:''' A Boolean value, which is ''''true'''' if, and only if, <math>K</math> is currently stored in the sequence.


'''Precondition:'''
'''Precondition:'''


'''Postcondition:''' If the output is '''''true''''', one occurrence of <math>K</math> is removed.
'''Postcondition:''' If the output is ''''true'''', one occurrence of <math>K</math> is removed.


== Known Implementations ==
== Known Implementations ==

Revision as of 16:06, 16 May 2015


General Information

Representation invariant:

  1. The abstract data structure ordered sequence implements sorted sequences as defined here.
  2. This abstract data structure is generic and parameterized by a fixed key type [math]\displaystyle{ \kappa }[/math].

Insert at position

Input: A key [math]\displaystyle{ K \in \kappa }[/math] and a nonnegative integral position [math]\displaystyle{ p }[/math].

Output: a Boolean value, which is true if, and only if, [math]\displaystyle{ p\in\{0,\ldots,n\} }[/math], where [math]\displaystyle{ n }[/math] is the length of the list.

Precondition:

Postcondition: If the output ist true, a new element with the key [math]\displaystyle{ K }[/math] is inserted at position [math]\displaystyle{ p }[/math].

Find

Input: A key [math]\displaystyle{ K \in \kappa }[/math].

Output: A Boolean value, which is true if, and only if, [math]\displaystyle{ K }[/math] is currently contained in the sequence.

Precondition:

Postcondition:

Remove

Input: A key [math]\displaystyle{ K \in \kappa }[/math].

Output: A Boolean value, which is 'true' if, and only if, [math]\displaystyle{ K }[/math] is currently stored in the sequence.

Precondition:

Postcondition: If the output is 'true', one occurrence of [math]\displaystyle{ K }[/math] is removed.

Known Implementations

  1. Linked list
  2. Doubly-linked list
  3. Array list