72 lines
1.6 KiB
C++
72 lines
1.6 KiB
C++
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#include <cstdio>
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using namespace std;
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template<
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typename TElem,
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std::size_t NSize>
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class HashList {
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private:
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typedef struct {
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std::size_t index;
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TElem elem;
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} entry;
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entry* entries[NSize];
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std::size_t create_hash(std::size_t const index, std::size_t const e) {
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return (index + e) % NSize;
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}
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public:
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HashList() {
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for(std::size_t i = 0; i < NSize; i++) entries[i] = NULL;
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}
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bool insert(std::size_t index, TElem elem) {
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std::size_t hash = 0;
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std::size_t e = 0;
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for(; e < NSize; e++) {
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hash = this->create_hash(index, e);
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if(entries[hash] == NULL) break;
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}
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printf("Inserting %d had %d collisions\n", index, e);
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if(entries[hash] != NULL) return false;
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entries[hash] = new entry{index,elem};
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return true;
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}
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entry* find(std::size_t index) {
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std::size_t hash = 0;
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std::size_t e = 0;
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for(; e < NSize; e++) {
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hash = this->create_hash(index, e);
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if(entries[hash] == NULL || entries[hash]->index == index) break;
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}
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printf("Finding %d had %d collisions\n", index, e);
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if(entries[hash] != NULL && entries[hash]->index != index) return NULL;
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return entries[hash];
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}
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};
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int main( int argc, char *argv[] ) {
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HashList<float, 13> l;
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l.insert(1024, 2.5f);
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l.insert(204, 1.5f);
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l.insert(217, 1.0f);
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printf("1024: %.1f\n", l.find(1024)->elem);
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printf("204: %.1f\n", l.find(204)->elem);
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printf("217: %.1f\n", l.find(217)->elem);
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return 0;
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}
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