hash collissions

LinearProbing.java

public class HashMap<Key,Value> {
   private int numPairs = 100000;
   private Value[] vals = (Value[]) new Object[numPairs];
   private Key[] keys = (Value[]) new Object[numPairs];
  
    private int hash(Key key) {
      return (key.hashCode() & 0x7fffffff) % M;
    }
  
    public  Value put(Key key, Value val) {
      int i;
      for (i = hash(key); keys[i] != null; i = (i+1)%M) {
        if (keys[i].equals(key))
          break;
        keys[i] = key;
        vals[i] = val;
      }
    }
    public  Value get(Key key) {
      for (int i = hash(key); keys[i] != null; i = (i+1)%M) {
        if (keys[i].equals(key))
          return vals[i]; 
      } 
      return null; 
    }
}

SeparateChaining.java

public class HashMap<Key,Value> {
   private int numChains = 100;
   private Node[] chainArray = new Node[numChains];
  
   private static class Node {
     private Object key;
     private Object val;
     private Node next;
   }
  
    private int hash(Key key) {
      return (key.hashCode() & 0x7fffffff) % M;
    }
  
    public  Value put(Key key, Value val) {
      int i = hash(key);
      for (Node x = chainArray[i]; x != null; x = x.next) {
        if (key.equals(x.key)) { 
          x.val = val; 
          return; 
        }
        chainArray[i] = new Node(key, val, chainArray[i]);
      }
    }
    public  Value get(Key key) {
      int i = hash(key);
      for (Node x = chainArray[i]; x != null; x = x.next) {
        if (key.equals(x.key)) 
          return (Value) x.val;
      }
      return null;  
    }
}