95 lines
2.0 KiB
C++
95 lines
2.0 KiB
C++
#ifndef DVEREB_DUALLOOKUP_H
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#define DVEREB_DUALLOOKUP_H
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#include <unordered_map>
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template <class T>
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class DualLookup {
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public:
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DualLookup();
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/* Add a mapped pair to the container
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* returns false if it already exists, regardless of direction
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* (i.e. value->equivilent is a duplicate of equivilent->value)
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*/
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bool add(T value, T equivilent);
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/* If found, Set result to the mapped value and true is returned.
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* If not found, result remains unchanged and false is returned.
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*/
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bool get(T key, T &result);
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/* If found, return true
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* else return false */
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bool contains(const T &key);
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private:
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std::unordered_map<T, T> owner;
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std::unordered_map<T, T> mirror;
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// NOTE(dev): These functions actually do the work:
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bool get_single(T key, T &result, const std::unordered_map<T, T> &umap);
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bool contains_single(const T &key, const std::unordered_map<T, T> &umap);
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};
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template <class T>
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DualLookup<T>::DualLookup()
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{
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}
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template <class T>
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bool DualLookup<T>::add(T value, T equivilent)
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{
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// already exists
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if(owner.find(value) != owner.end() || mirror.find(value) != mirror.end())
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return false;
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if(owner.find(equivilent) != owner.end() || mirror.find(equivilent) != mirror.end())
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return false;
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owner.insert({value, equivilent});
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mirror.insert({equivilent, value});
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return true;
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}
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template <class T>
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bool DualLookup<T>::get(T key, T &result)
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{
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if(get_single(key, result, owner))
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return true;
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if(get_single(key, result, mirror))
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return true;
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return false; // didn't find it
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}
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template <class T>
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bool DualLookup<T>::contains(const T &key)
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{
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if(contains_single(key, owner))
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return true;
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if(contains_single(key, mirror))
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return true;
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return false; // didn't find it
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}
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template <class T>
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bool DualLookup<T>::get_single(T key, T &result, const std::unordered_map<T, T> &umap)
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{
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auto i = umap.find(key);
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if(i == umap.end())
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return false;
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result = i->second;
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return true;
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}
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template <class T>
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bool DualLookup<T>::contains_single(const T &key, const std::unordered_map<T, T> &umap)
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{
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return umap.find(key) != umap.end();
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}
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#endif
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