hash table - linear probing

Author: ivanmmarkovic

hash-table/linear-probing.py

@@ -0,0 +1,121 @@
+
+class HashMap:
+    def __init__(self, length: int = 11):
+        self._length: int = length
+        self._keys: list = [None] * self._length
+        self._values: list = [None] * self._length
+        self._elements_count: int = 0
+
+    def put(self, key: int, value: str):
+        hash: int = self.hash(key)
+        if self._keys[hash] is None or self._keys[hash] == "deleted" or self._keys[hash] == key:
+            if self._keys[hash] is None or self._keys[hash] == "deleted":
+                self._elements_count += 1
+            self._keys[hash] = key
+            self._values[hash] = value
+        else:
+            new_hash: int = self.rehash(hash)
+            while new_hash != hash and self._keys[new_hash] is not None and self._keys[new_hash] != "deleted"\
+                    and self._keys[new_hash] != key:
+                new_hash = self.rehash(new_hash)
+            if self._keys[new_hash] is None or self._keys[new_hash] == "deleted" or self._keys[new_hash] == key:
+                if self._keys[new_hash] is None or self._keys[new_hash] == "deleted":
+                    self._elements_count += 1
+                self._keys[new_hash] = key
+                self._values[new_hash] = value
+
+    def get(self, key: int):
+        hash: int = self.hash(key)
+        if self._keys[hash] is None:
+            return None
+        elif self._keys[hash] == key:
+            return self._values[hash]
+        else:
+            new_hash: int = self.rehash(hash)
+            while new_hash != hash and self._keys[new_hash] is not None and self._keys[new_hash] != key:
+                new_hash = self.rehash(new_hash)
+            if self._keys[new_hash] is None:
+                return None
+            elif self._keys[new_hash] == key:
+                return self._values[new_hash]
+            else:
+                return None
+
+    def contains(self, key: int) -> bool:
+        hash: int = self.hash(key)
+        if self._keys[hash] is None:
+            return False
+        elif self._keys[hash] == key:
+            return True
+        else:
+            new_hash: int = self.rehash(hash)
+            while new_hash != hash and self._keys[new_hash] is not None and self._keys[new_hash] != key:
+                new_hash = self.rehash(new_hash)
+            if self._keys[new_hash] is None:
+                return False
+            elif self._keys[new_hash] == key:
+                return True
+            else:
+                return False
+
+    def delete(self, key):
+        hash: int = self.hash(key)
+        if self._keys[hash] is None:
+            return
+        elif self._keys[hash] == key:
+            self._elements_count -= 1
+            self._keys[hash] = "deleted"
+            self._values[hash] = None
+        else:
+            new_hash: int = self.rehash(hash)
+            while new_hash != hash and self._keys[new_hash] is not None and self._keys[new_hash] != key:
+                new_hash = self.rehash(new_hash)
+            if self._keys[new_hash] == key:
+                self._elements_count -= 1
+                self._keys[new_hash] = "deleted"
+                self._values[new_hash] = None
+
+    def size(self) -> int:
+        return self._elements_count
+
+    def hash(self, key: int) -> int:
+        return key % self._length
+
+    def rehash(self, old_hash: int):
+        return (old_hash + 1) % self._length
+
+
+hm: HashMap = HashMap()
+hm.put(11, "string 11")
+hm.put(22, "string 22")
+hm.put(33, "string 33")
+hm.put(44, "string 44")
+hm.put(12, "string 12")
+hm.put(21, "string 21")
+
+print(hm._keys)
+print(hm._values)
+
+print("Get 11", hm.get(11))
+print("Get 33", hm.get(33))
+print("Get 21", hm.get(21))
+print("Get 7", hm.get(7))
+
+print("Contains key 7", hm.contains(7))
+print("Contains key 33", hm.contains(33))
+
+
+print("Delete key 7", hm.delete(7))
+print("Delete key 33", hm.delete(33))
+
+print("Contains key 33", hm.contains(33))
+
+print(hm._keys)
+print(hm._values)
+
+hm.put(14, "string 14")
+
+print("Contains key 33", hm.contains(33))
+
+print(hm._keys)
+print(hm._values)