64 lines
1.7 KiB
C
64 lines
1.7 KiB
C
#ifndef LIBABACUS_TRIE_H
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#define LIBABACUS_TRIE_H
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#include "ll.h"
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#include "result.h"
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/**
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* A node in the trie.
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*/
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struct libab_trie_node_s {
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/**
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* The "child" node, which points
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* to the next layer of the trie, housing
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* children that have a prefix ending in this node's key value.
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*/
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struct libab_trie_node_s* child;
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/**
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* The "next" node, which points
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* to the sibiling of this tree, wich has the same prefix
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* as this node.
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*/
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struct libab_trie_node_s* next;
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/**
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* The values associated with the key ending with
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* this node's key value.
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*/
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ll values;
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/**
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* The last letter of the key, which this node represents.
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* The remainder of the key is encoded in nodes preceding this one.
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*/
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char key;
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};
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/**
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* A struct that represents a trie.
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*/
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struct libab_trie_s {
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/**
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* The first search node in this trie.
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*/
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struct libab_trie_node_s* head;
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/**
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* The empty list returned if no value is found.
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* Note that existing nodes return their own linked
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* list of values, even if empty. However, for keys
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* that don't exist as prefixes in the trie,
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* this list is returned to maintain consistency:
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* a list is always returned containing the values
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* of the trie associated with the given key.
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*/
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ll empty_list;
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};
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typedef struct libab_trie_s libab_trie;
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typedef struct libab_trie_node_s libab_trie_node;
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void libab_trie_init(libab_trie* trie);
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libab_result libab_trie_put(libab_trie* trie, const char* key, void* value);
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const ll* libab_trie_get(libab_trie* trie, const char* key);
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void libab_trie_free(libab_trie* trie);
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#endif
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