Functions such as insert,search,delete is written

hash_table1.cpp

@@ -0,0 +1,332 @@
+#adding different functions to use hash tables
+ /*
+
+     *C++ Program to Implement Hash Tables
+
+     */
+
+    #include<iostream>
+
+    #include<cstdlib>
+
+    #include<string>
+
+    #include<cstdio>
+
+    using namespace std;
+
+    const int TABLE_SIZE = 128;
+
+
+
+    /*
+
+     * HashEntry Class Declaration
+
+     */
+
+    class HashEntry
+
+    {
+
+        public:
+
+            int key;
+
+            int value;
+
+            HashEntry(int key, int value)
+
+            {
+
+                this->key = key;
+
+                this->value = value;
+
+            }
+
+    };
+
+
+
+    /*
+
+     * HashMap Class Declaration
+
+     */
+
+    class HashMap
+
+    {
+
+        private:
+
+            HashEntry **table;
+
+        public:   
+
+            HashMap()
+
+    	{
+
+                table = new HashEntry * [TABLE_SIZE];
+
+                for (int i = 0; i< TABLE_SIZE; i++)
+
+                {
+
+                    table[i] = NULL;
+
+                }
+
+            }
+
+            /*
+
+             * Hash Function
+
+             */
+
+            int HashFunc(int key)
+
+            {
+
+                return key % TABLE_SIZE;
+
+            }
+
+            /*
+
+             * Insert Element at a key
+
+             */
+
+    	void Insert(int key, int value)
+
+    	{
+
+                int hash = HashFunc(key);
+
+                while (table[hash] != NULL && table[hash]->key != key)
+
+                {
+
+                    hash = HashFunc(hash + 1);
+
+                }
+
+                if (table[hash] != NULL)
+
+                    delete table[hash];
+
+                table[hash] = new HashEntry(key, value);
+
+    	}
+
+            /*
+
+             * Search Element at a key
+
+             */
+
+            int Search(int key)
+
+    	{
+
+    	    int  hash = HashFunc(key);
+
+    	    while (table[hash] != NULL && table[hash]->key != key)
+
+    	    {
+
+    	        hash = HashFunc(hash + 1);
+
+    	    }
+
+    	    if (table[hash] == NULL)
+
+    	        return -1;
+
+    	    else
+
+    	        return table[hash]->value;
+
+            }
+
+
+
+            /*
+
+             * Remove Element at a key
+
+             */
+
+            void Remove(int key)
+
+    	{
+
+    	    int hash = HashFunc(key);
+
+    	    while (table[hash] != NULL)
+
+    	    {
+
+    	        if (table[hash]->key == key)
+
+    	            break;
+
+    	        hash = HashFunc(hash + 1);
+
+    	    }
+
+                if (table[hash] == NULL)
+
+    	    {
+
+                    cout<<"No Element found at key "<<key<<endl;
+
+                    return;
+
+                }
+
+                else
+
+                {
+
+                    delete table[hash];
+
+                }
+
+                cout<<"Element Deleted"<<endl;
+
+            }
+
+            ~HashMap()
+
+    	{
+
+                for (int i = 0; i < TABLE_SIZE; i++)
+
+                {
+
+                    if (table[i] != NULL)
+
+                        delete table[i];
+
+                    delete[] table;
+
+                }
+
+            }
+
+    };
+
+    /*
+
+     * Main Contains Menu
+
+     */
+
+    int main()
+
+    {
+
+        HashMap hash;
+
+        int key, value;
+
+        int choice;
+
+        while (1)
+
+        {
+
+            cout<<"\n----------------------"<<endl;
+
+            cout<<"Operations on Hash Table"<<endl;
+
+            cout<<"\n----------------------"<<endl;
+
+            cout<<"1.Insert element into the table"<<endl;
+
+            cout<<"2.Search element from the key"<<endl;
+
+            cout<<"3.Delete element at a key"<<endl;
+
+            cout<<"4.Exit"<<endl;
+
+            cout<<"Enter your choice: ";
+
+            cin>>choice;
+
+            switch(choice)
+
+            {
+
+            case 1:
+
+                cout<<"Enter element to be inserted: ";
+
+                cin>>value;
+
+                cout<<"Enter key at which element to be inserted: ";
+
+                cin>>key;
+
+                hash.Insert(key, value);
+
+                break;
+
+            case 2:
+
+                cout<<"Enter key of the element to be searched: ";
+
+                cin>>key;
+
+                if (hash.Search(key) == -1)
+
+                {
+
+    	        cout<<"No element found at key "<<key<<endl;
+
+    	        continue;
+
+    	    }
+
+    	    else
+
+    	    {
+
+    	        cout<<"Element at key "<<key<<" : ";
+
+    	        cout<<hash.Search(key)<<endl;
+
+    	    }
+
+                break;
+
+            case 3:
+
+                cout<<"Enter key of the element to be deleted: ";
+
+                cin>>key;
+
+                hash.Remove(key);
+
+                break;
+
+            case 4:
+
+                exit(1);
+
+            default:
+
+               cout<<"\nEnter correct option\n";
+
+           }
+
+        }
+
+        return 0;
+
+    }