Using a Sentinel Value to Find an Element in a List

[evinda]

Hi! (Smile)

If we want to look for an element $x$ in a list, we can use a sentinel value.
What do we gain, with the use of a sentinel value?

 

[I like Serena]

Hi! (Smile)

If we want to look for an element $x$ in a list, we can use a sentinel value.
What do we gain, with the use of a sentinel value?

Hey! (Wave)

From wiki:

A sentinel node is a specifically designated node used with linked lists and trees as a traversal path terminator. A sentinel node does not hold or reference any data managed by the data structure. Sentinels are used as an alternative over using null as the path terminator in order to get one or more of the following benefits:

1. Increased speed of operations
2. Reduced algorithmic complexity and code size
3. Increased data structure robustness (arguably)​

(Nerd)

 

[evinda]

Hey! (Wave)

From wiki:

A sentinel node is a specifically designated node used with linked lists and trees as a traversal path terminator. A sentinel node does not hold or reference any data managed by the data structure. Sentinels are used as an alternative over using null as the path terminator in order to get one or more of the following benefits:

1. Increased speed of operations
2. Reduced algorithmic complexity and code size
3. Increased data structure robustness (arguably)​

(Nerd)

Why do we have the above benefits? Because of the fact that if we are looking for an element, we do not have to check the case that the element does not exist? (Thinking)

 

[I like Serena]

Why do we have the above benefits? Because of the fact that if we are looking for an element, we do not have to check the case that the element does not exist? (Thinking)

You've answered your own question! (Clapping)

 

[evinda]

You've answered your own question! (Clapping)

Great! Thanks a lot! (Music)