mirror of
https://github.com/autistic-symposium/master-algorithms-py.git
synced 2025-04-29 20:26:07 -04:00
Update README.md
This commit is contained in:
parent
dd2462222f
commit
38f6c1491a
@ -85,6 +85,111 @@
|
||||
|
||||
<br>
|
||||
|
||||
```python
|
||||
class HashSet:
|
||||
|
||||
def __init__(self):
|
||||
self.size = 131
|
||||
self.bucket = [Bucket() for _ in range(self.size)]
|
||||
|
||||
def _get_hash_key(self, key):
|
||||
return key % self.size
|
||||
|
||||
def add(self, element: int) -> None:
|
||||
bucket_index = self._get_hash_key(element)
|
||||
self.bucket[bucket_index].insert(element)
|
||||
|
||||
def remove(self, element: int) -> None:
|
||||
bucket_index = self._get_hash_key(element)
|
||||
self.bucket[bucket_index].delete(element)
|
||||
|
||||
def contains(self, element: int) -> bool:
|
||||
bucket_index = self._get_hash_key(element)
|
||||
return self.bucket[bucket_index].exists(element)
|
||||
|
||||
|
||||
class Node:
|
||||
def __init__(self, value=None):
|
||||
self.val = value
|
||||
self.left = None
|
||||
self.right = None
|
||||
|
||||
|
||||
class Bucket:
|
||||
def __init__(self):
|
||||
self.tree = BSTree()
|
||||
|
||||
def insert(self, value):
|
||||
self.tree.root = self.tree.insert(self.tree.root, value)
|
||||
|
||||
def delete(self, value):
|
||||
self.tree.root = self.tree.delete(self.tree.root, value)
|
||||
|
||||
def exists(self, value):
|
||||
return (self.tree.search(self.tree.root, value) is not None)
|
||||
|
||||
|
||||
class BSTree():
|
||||
def __init__(self):
|
||||
self.root = None
|
||||
|
||||
def search(self, root, value) -> Node:
|
||||
if root is None or value == root.val:
|
||||
return root
|
||||
|
||||
return self.search(root.left, value) if val < root.value \
|
||||
else self.search(root.right, value)
|
||||
|
||||
def insert(self, root, value) -> Node:
|
||||
if not root:
|
||||
return Node(value)
|
||||
|
||||
if value > root.val:
|
||||
root.right = self.insert(root.right, value)
|
||||
elif value == root.val:
|
||||
return root
|
||||
else:
|
||||
root.left = self.insert(root.left, value)
|
||||
|
||||
def successor(self, root):
|
||||
# one step right and then all left
|
||||
root = root.right
|
||||
while root.left:
|
||||
root = root.left
|
||||
return root.value
|
||||
|
||||
def predecessor(self, root):
|
||||
# one step left and then always right
|
||||
root = root.left
|
||||
while root.right:
|
||||
root = root.right
|
||||
return root.value
|
||||
|
||||
def delete(self, root, key) -> TreeNode:
|
||||
if not root:
|
||||
return None
|
||||
|
||||
if key > root.val:
|
||||
root.right = self.delete(root.right, key)
|
||||
|
||||
elif key < root.val:
|
||||
root.left = self.delete(root.left, key)
|
||||
|
||||
else:
|
||||
if not (root.left or root.right):
|
||||
root = None
|
||||
elif root.right:
|
||||
root.val = self.sucessor(root)
|
||||
root.right = self.delete(root.right, root.val)
|
||||
else:
|
||||
root.val = self.predecessor(root)
|
||||
root.left = self.delete(root.left, root.val)
|
||||
|
||||
return root
|
||||
```
|
||||
|
||||
<br>
|
||||
|
||||
----
|
||||
|
||||
### implementing a hash map
|
||||
@ -97,3 +202,61 @@
|
||||
|
||||
<br>
|
||||
|
||||
```python
|
||||
#!/usr/bin/env python3
|
||||
# -*- coding: utf-8 -*-
|
||||
# author: bt3gl
|
||||
|
||||
|
||||
class Bucket:
|
||||
|
||||
def __init__(self):
|
||||
self.bucket = []
|
||||
|
||||
def get(self, key):
|
||||
for (k, v) in self.bucket:
|
||||
if k == key:
|
||||
return v
|
||||
return -1
|
||||
|
||||
def put(self, key, value):
|
||||
found = False
|
||||
for i, k in enumerate(self.bucket):
|
||||
if key == k[0]:
|
||||
self.bucket[i] = (key, value)
|
||||
found = True
|
||||
break
|
||||
if not found:
|
||||
self.bucket.append((key, value))
|
||||
|
||||
def remove(self, key):
|
||||
for i, k in enumerate(self.bucket):
|
||||
if key == k[0]:
|
||||
# del is an O(N) operation, as we would copy all the i: elements
|
||||
# to make it O(1) we could swap the element we want to remove
|
||||
# with the last element in the bucket
|
||||
del self.bucket[i]
|
||||
|
||||
|
||||
class HashMap:
|
||||
|
||||
def __init__(self, key_space):
|
||||
self.size = size
|
||||
self.table = [Bucket() for _ in range(self.size)]
|
||||
|
||||
def _get_hash_key(self, key):
|
||||
return key % self.size
|
||||
|
||||
def put(self, key: int, value: int):
|
||||
hash_key = self._get_hash_key(key)
|
||||
self.table[hash_key].put(key, value)
|
||||
|
||||
def get(self, key: int):
|
||||
hash_key = self._get_hash_key(key)
|
||||
return self.table[hash_key].get(key)
|
||||
|
||||
def remove(self, key: int):
|
||||
hash_key = self._get_hash_key(key)
|
||||
self.table[hash_key].remove(key)
|
||||
```
|
||||
|
||||
|
Loading…
x
Reference in New Issue
Block a user