hash_set.hpp

#pragma once
 
#include "DSCEngine/types/hash.hpp"
#include "DSCEngine/types/vector.hpp"
#include "DSCEngine/debug/assert.hpp"
 
namespace DSC
{
    template<typename T, int (*H)(const T&) = default_hash<T, 128>, int S = 128>
    class HashSet
    {
    private:
        Vector<T> container[S];
    public:
        void add(const T& item);
        void remove(const T& item);     
        bool includes(const T& item) const;     
    };
    
    template<typename T, int (*H)(const T&), int S>
    void HashSet<T,H,S>::add(const T& item)
    {
        int h = H(item);
        nds_assert(0<=h && h<S);
        
        bool found = false;
        for(int i=0;i<container[h].size() && !found;i++)
            found = (container[h][i]==item);
        
        if(found) return;
        container[h].push_back(item);               
    }
    
    template<typename T, int (*H)(const T&), int S>
    void HashSet<T,H,S>::remove(const T& item)
    {
        int h = H(item);
        nds_assert(0<=h && h<S);        
        container[h].remove(item);
    }
    
    template<typename T, int (*H)(const T&), int S>
    bool HashSet<T,H,S>::includes(const T& item) const
    {
        int h = H(item);
        nds_assert(0<=h && h<S);
        
        for(int i=0;i<container[h].size();i++)
            if(container[h][i]==item)
                return true;
        return false;   
    }
}