Objective : To implement a Hash Table
Input: A set of pairs of keys and values
Approach:
- Create a Hash Table
- Hashtable<Integer, String> ht = new Hashtable<Integer, String>();
- Insert values in hash table using put(key,value)
- ht.put(key, value);
- Get values from hash table using get(key)
- ht.get(key);
Advantage : The search time for any element is O(1) since it uses key to find an element so it takes constant time. But drawback is that it takes extra space.
Complete Code:
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| import java.util.Hashtable; | |
| public class SimpleHashTable { | |
| int [] a = new int[5]; | |
| String [] arrNames = new String[]{"Sumit","Jain","Raghav","Garg","Gaurav","Rishi"}; | |
| Hashtable<Integer, String> ht = new Hashtable<Integer, String>(); | |
| public void insertValues(){ | |
| for(int i=0;i<arrNames.length;i++ ){ | |
| ht.put(i+1,arrNames[i]); | |
| } | |
| } | |
| public String getValue(int key){ | |
| return ht.get(key); | |
| } | |
| public static void main (String [] args){ | |
| SimpleHashTable sht = new SimpleHashTable(); | |
| sht.insertValues(); | |
| System.out.println("All values inserted"); | |
| System.out.println("Employee with ID 1 is "+ sht.getValue(1)); | |
| System.out.println("Employee with ID 3 is "+ sht.getValue(6)); | |
| } | |
| } |
Output:
All values inserted Employee with ID 1 is Sumit Employee with ID 3 is Rishi