127 lines
4.0 KiB
Python
127 lines
4.0 KiB
Python
class HashTable:
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def __init__(self, capacity=10):
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if type(capacity) is not int or isinstance(capacity, bool):
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raise TypeError("Kapacita musí byť celé číslo.")
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if capacity <= 0:
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raise ValueError("Kapacita musí byť kladné celé číslo.")
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self._capacity = capacity
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self.empty = object()
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self.deleted = object()
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self.slots = [self.empty] * capacity
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self.count = 0
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@property
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def capacity(self):
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return self._capacity
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def hash(self, key):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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h = 0
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for znak in key:
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h = (31 * h + ord(znak)) % self._capacity
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return h
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def probe(self, key):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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start_idx = self.hash(key)
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first_deleted = None
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for krok in range(self._capacity):
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idx = (start_idx + krok) % self._capacity
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slot = self.slots[idx]
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if slot is self.empty:
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return first_deleted if first_deleted is not None else idx
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elif slot is self.deleted:
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if first_deleted is None:
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first_deleted = idx
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elif slot[0] == key:
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return idx
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if first_deleted is not None:
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return first_deleted
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raise RuntimeError("Tabuľka je plná a nemá žiadne voľné ani vymazané miesto.")
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def load_factor(self):
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return self.count / self._capacity
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def __getitem__(self, key):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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idx = self.probe(key)
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slot = self.slots[idx]
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if slot is not self.empty and slot is not self.deleted and slot[0] == key:
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return slot[1]
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raise KeyError(key)
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def __setitem__(self, key, value):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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start_idx = self.hash(key)
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existing_idx = None
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for krok in range(self._capacity):
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idx = (start_idx + krok) % self._capacity
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slot = self.slots[idx]
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if slot is self.empty:
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break
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if slot is not self.deleted and slot[0] == key:
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existing_idx = idx
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break
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if existing_idx is not None:
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self.slots[existing_idx] = (key, value)
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return
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if (self.count + 1) / self._capacity > 0.7:
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self._resize(self._capacity * 2)
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idx = self.probe(key)
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self.slots[idx] = (key, value)
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self.count += 1
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def _resize(self, new_capacity):
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old_slots = self.slots
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self._capacity = new_capacity
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self.slots = [self.empty] * new_capacity
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self.count = 0
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for slot in old_slots:
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if slot is not self.empty and slot is not self.deleted:
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k, v = slot
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idx = self.probe(k)
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self.slots[idx] = (k, v)
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self.count += 1
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def __delitem__(self, key):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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idx = self.probe(key)
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slot = self.slots[idx]
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if slot is not self.empty and slot is not self.deleted and slot[0] == key:
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self.slots[idx] = self.deleted
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self.count -= 1
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return
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raise KeyError(key)
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def __contains__(self, key):
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if not isinstance(key, str):
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raise TypeError("Kľúč musí byť reťazec.")
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try:
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idx = self.probe(key)
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except RuntimeError:
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return False
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slot = self.slots[idx]
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return slot is not self.empty and slot is not self.deleted and slot[0] == key
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def __len__(self):
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return self.count
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def __iter__(self):
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for slot in self.slots:
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if slot is not self.empty and slot is not self.deleted:
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yield slot[0] |