Open Addressing in C++

Author: Deepali-Srivastava

Diff for: hashing/open-addressing/Demo.cpp

@@ -0,0 +1,70 @@
+/*
+Copyright (C) Deepali Srivastava - All Rights Reserved
+This code is part of DSA course available on CourseGalaxy.com    
+*/
+
+#include<iostream>
+#include<string>
+#include"hashtable.h"
+
+using namespace std;
+
+int main()
+{
+	int id, choice, size;
+	string name;
+		
+	cout << "Enter initial size of table : ";
+    cin >> size;
+			
+	HashTable table(size);
+		
+	while(true)
+	{
+	   cout << "1.Insert a record \n";
+	   cout << "2.Search a record \n";
+	   cout << "3.Delete a record \n";
+	   cout << "4.Display table  \n";
+	   cout << "5.Exit \n";
+	   cout << "Enter your choice : ";
+       cin >> choice;
+
+	   if( choice == 5 )
+		   break;
+	   
+	   switch( choice )
+	   {
+			case 1 : 
+				cout << "Enter student id : ";
+                cin >> id;
+				cout << "Enter student name : ";
+                cin >> name;
+				table.insertRecord(StudentRecord(id,name));
+				break;
+			case 2 : 
+			    cout << "Enter a key to be searched : ";
+			    cin >> id; 
+			  				   
+			    if( table.searchRecord(id) )
+				    cout << "Key found \n";
+				else
+					cout << "Key not found \n";
+				break;
+			case 3: 
+			    cout << "Enter a key to be deleted : ";
+			    cin >> id;
+			    table.deleteRecord(id);
+			    break;
+			case 4:
+			    table.displayTable();
+			    break;
+			case 5:
+			    exit(1);
+				break;
+			default:
+				cout << "Wrong choice : \n";
+		  }
+	 }
+}
+    
+

Diff for: hashing/open-addressing/HashTable.cpp

@@ -0,0 +1,119 @@
+/*
+Copyright (C) Deepali Srivastava - All Rights Reserved
+This code is part of DSA course available on CourseGalaxy.com    
+*/
+
+#include<iostream>
+#include"hashtable.h"
+
+using namespace std;
+
+#define EMPTY 0
+#define DELETED 1
+#define OCCUPIED 2
+
+HashTable :: HashTable(int tableSize)
+{
+	m = tableSize;
+    arr = new StudentRecord[m];
+	status = new int[m];
+
+	for( int i=0; i<m; i++ )
+		status[i] = EMPTY;
+    
+	n = 0;
+}
+
+HashTable :: ~HashTable()
+{
+	delete[] arr;
+	delete[] status;
+}
+
+int HashTable :: hash(int key)
+{
+	return key % m;
+}
+
+void HashTable :: insertRecord(StudentRecord newRecord)
+{
+	int key = newRecord.getstudentId();
+    int h = hash(key);
+
+    int location = h;
+
+    for( int i=1; i<m; i++ )
+    {
+		if( status[location] == EMPTY || status[location] == DELETED  )
+		{
+			arr[location] = newRecord;
+			n++;
+			status[location] = OCCUPIED;
+            return;
+        }
+
+        if( arr[location].getstudentId() == key )
+		{
+			cout << "Duplicate key \n";
+		    return;
+		}
+
+        location = (h + i) % m;
+     }
+     cout << "Table is full : Record can't be inserted \n";
+}
+
+bool HashTable :: searchRecord(int key)
+{
+	int h = hash(key);
+    int location = h;
+
+    for( int i=1; i<m; i++)
+    {
+		if( status[location] == EMPTY || status[location] == DELETED )
+			return false;
+        if( arr[location].getstudentId() == key )
+        {
+			cout << arr[location] << "\n";
+			return true; 
+		}
+        location = (h + i) % m;
+     }
+     return false;
+}
+
+void HashTable :: deleteRecord(int key)
+{
+	int h = hash(key);
+    int location = h;
+
+    for( int i=1; i<m; i++ )
+    {
+		if( status[location] == EMPTY || status[location] == DELETED  )
+		{
+			cout << "Key not found\n";
+			return;
+		}
+        if( arr[location].getstudentId() == key )
+        {
+			status[location] = DELETED;
+            n--;
+            cout <<"Record " << arr[location] << " deleted\n";
+			return;
+        }
+        location = (h + i) % m;
+     }
+}
+
+void HashTable :: displayTable()
+{
+	for( int i=0; i<m; i++ )
+    {
+		cout << "[" << i << "]  -->  ";
+
+        if( status[i] == OCCUPIED )
+			cout << arr[i] << "\n";
+        else
+            cout << "___" << "\n";
+     }
+}

Diff for: hashing/open-addressing/StudentRecord.cpp

@@ -0,0 +1,35 @@
+/*
+Copyright (C) Deepali Srivastava - All Rights Reserved
+This code is part of DSA course available on CourseGalaxy.com    
+*/
+
+#include<iostream>
+#include<string>
+#include"student.h"
+
+using namespace std;
+
+StudentRecord :: StudentRecord()
+{ }
+
+StudentRecord :: StudentRecord(int i, string name)
+{
+	studentId = i;
+    studentName = name;
+}
+
+int StudentRecord :: getstudentId()
+{
+	return studentId;
+}
+
+void StudentRecord :: setstudentId(int i)
+{
+	studentId = i;
+}
+        
+ostream& operator<<(ostream& out, const StudentRecord& st)
+{
+	out << " " << st.studentId << " " << st.studentName << "  " ;
+	return out;
+}

Diff for: hashing/open-addressing/hashtable.h

@@ -0,0 +1,25 @@
+/*
+Copyright (C) Deepali Srivastava - All Rights Reserved
+This code is part of DSA course available on CourseGalaxy.com    
+*/
+
+#include<iostream>
+#include"student.h"
+using namespace std;
+
+class HashTable
+{
+	 StudentRecord *arr;
+     int m;  //size of the array
+     int n;  //number of records
+	 int *status;
+	 int hash(int key);
+  
+  public:
+	 HashTable(int tableSize=11);
+     ~HashTable();
+	 void insertRecord(StudentRecord newRecord);
+	 bool searchRecord(int key);
+     void deleteRecord(int key);
+	 void displayTable();
+};

Diff for: hashing/open-addressing/student.h

@@ -0,0 +1,20 @@
+/*
+Copyright (C) Deepali Srivastava - All Rights Reserved
+This code is part of DSA course available on CourseGalaxy.com    
+*/
+
+#include<iostream>
+using namespace std;
+
+class StudentRecord
+{
+	  int studentId;
+      string studentName;
+	
+   public:
+	  StudentRecord();
+	  StudentRecord(int i, string name);
+      int getstudentId();
+      void setstudentId(int i);
+      friend ostream& operator<<(ostream& out, const StudentRecord& st);
+};