4.6 KiB
| title | TARGET DECK | FILE TAGS | tags | |
|---|---|---|---|---|
| Direct Addressing | Obsidian::STEM | hashing::direct |
|
Overview
Given a universe of keys U = \{0, 1, \ldots, m - 1\}, a direct-address table has m slots. Each slot corresponds to a key in universe U.
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Basic
Given universe U, how many slots must a direct-address table have?
Back: |U|
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
%%ANKI Basic What name is given to each position in a direct-address table? Back: A slot. Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
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Basic
Given a direct-address table, the element at slot k has what key?
Back: k.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
%%ANKI
Basic
Given a direct-address table, an element with key k is placed in what slot?
Back: The $k$th slot.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
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Basic
Write pseudocode to test membership of x in direct-address table T[0:m-1].
Back:
bool membership(T, x) {
return T[x.key] != NIL;
}
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
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Basic
What is the worst-cast runtime complexity of direct-address table searches?
Back: O(1)
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
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Basic
Write pseudocode to insert x into direct-address table T[0:m-1].
Back:
void insert(T, x) {
T[x.key] = x;
}
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
%%ANKI
Basic
What is the worst-case runtime complexity of direct-address table insertions?
Back: O(1)
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
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Basic
Write pseudocode to delete x from direct-address table T[0:m-1].
Back:
void delete(T, x) {
T[x.key] = NIL;
}
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
END%%
%%ANKI
Basic
What is the worst-cast runtime complexity of direct-address table deletions?
Back: O(1)
Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
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%%ANKI Basic In what situation does direct addressing waste space? Back: When the number of keys used is less than the size of the universe. Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
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%%ANKI Basic In what situation is direct addressing impossible? Back: When the size of the universe is too large to hold in memory. Reference: Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).
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%%ANKI Basic What distinguishes direct addressing from closed and open addressing? Back: Direct addressing isn't concerned with conflicting keys. Reference: “Hash Tables: Open vs Closed Addressing | Programming.Guide,” accessed June 12, 2024, https://programming.guide/hash-tables-open-vs-closed-addressing.html.
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%%ANKI Basic Direct addressing sits between what other addressing types? Back: Open and closed addressing. Reference: “Hash Tables: Open vs Closed Addressing | Programming.Guide,” accessed June 12, 2024, https://programming.guide/hash-tables-open-vs-closed-addressing.html.
END%%
Bibliography
- “Hash Tables: Open vs Closed Addressing | Programming.Guide,” accessed June 12, 2024, https://programming.guide/hash-tables-open-vs-closed-addressing.html.
- Thomas H. Cormen et al., Introduction to Algorithms, Fourth edition (Cambridge, Massachusett: The MIT Press, 2022).