hashset

hash.cpp

@@ -0,0 +1,109 @@
+#include <string>
+#include <iostream>
+ 
+using namespace std;
+ 
+// https://fit-wiki.cz/%C5%A1kola/p%C5%99edm%C4%9Bty/bi-pa2/pa2_zkou%C5%A1ka_2019-05-23
+
+struct TItem {
+    TItem(string key, string val, TItem *nextHash, TItem *nextOrd, TItem *prevOrd)
+        : m_Key(key), m_Val(val), m_NextHash(nextHash), m_NextOrder(nextOrd), m_PrevOrder(prevOrd) {}
+ 
+    string m_Key, m_Val;
+    TItem *m_NextHash, *m_NextOrder, *m_PrevOrder;
+};
+ 
+class CHash {
+public:
+
+    CHash(int m) : m_Table(NULL), m_Size(m), m_FirstOrder(NULL), m_LastOrder(NULL) {
+        m_Table = new TItem *[m];
+        for (int i = 0; i < m; i++)
+            m_Table[i] = NULL;
+    }
+
+    ~CHash() {
+        for (size_t i = 0; i < m_Size; ++i)
+            delete m_Table[i];
+        delete[] m_Table;
+    }
+
+    CHash(CHash &) = delete;
+    CHash &operator=(CHash &) = delete;
+ 
+    bool Ins(string key, string val) {
+        if (!m_FirstOrder)
+            return m_Table[ hashFn(key) ] = m_FirstOrder = m_LastOrder = new TItem(key, val, nullptr, nullptr, nullptr);
+        
+        TItem** i = &m_Table[ hashFn(key) ];
+        
+        if (!*i) {
+            return m_LastOrder = *i = m_LastOrder->m_NextOrder = new TItem(key, val, nullptr, nullptr, nullptr);
+        }
+
+        TItem* j = *i;
+        while(j->m_NextHash) {
+            if (j->m_Key == key) return false;
+            j = j->m_NextHash;
+        }
+
+        if (j->m_Key == key) return false;
+        return j->m_NextHash = m_LastOrder = new TItem(key, val, nullptr, nullptr, nullptr);
+    }
+
+
+
+    bool IsSet(string key) {
+        TItem *tmp = m_Table[hashFn(key)];
+        while (tmp != NULL && tmp->m_Key != key)
+            tmp = tmp->m_NextHash;
+        if (tmp == NULL)
+            return false;
+        return true;
+    }
+
+    template <typename func>
+    void ForEach(func f) {
+        TItem *tmp = m_FirstOrder;
+        while (tmp != NULL)
+        {
+            f(tmp);
+            tmp = tmp->m_NextOrder;
+        }
+    }
+ 
+private:
+    TItem **m_Table;
+    unsigned int m_Size;
+    TItem *m_FirstOrder, *m_LastOrder;
+    unsigned int hashFn(string &str) {
+        std::hash<std::string> hash_fn;
+        return hash_fn(str) % m_Size;
+    }
+
+};
+ 
+
+
+
+
+
+
+
+
+
+
+int main(int argc, char **argv) {
+    CHash hashtable(100);
+    hashtable.Ins("h1", "car");
+    hashtable.Ins("h1", "phone");
+    hashtable.Ins("h2", "field");
+    hashtable.Ins("h3", "house");
+    hashtable.Ins("h4", "tree");
+ 
+    hashtable.ForEach([](TItem *it) {
+        cout << it->m_Key << " - " << it->m_Val << endl;
+    });
+ 
+    return 0;
+}