Explanation
- **Zobrist Hashing** is a hashing technique used in computer games (like chess) to represent game states efficiently. It works by assigning a random bitstring to each possible move or position, then XORing the bitstrings together to create a unique hash for the current game state.
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Steps
- Assign a random bitstring to each possible position or move.
- For each move, XOR the corresponding bitstrings together to update the hash.
- The resulting hash represents the current game state.
Time Complexity
- O(1) for each update or calculation, as XOR operations are constant-time.
import random
class ZobristHashing:
def __init__(self, size):
self.size = size
self.table = [[random.getrandbits(64) for _ in range(2)] for _ in range(size)]
self.hash_value = 0
def update(self, index, bit):
self.hash_value ^= self.table[index][bit]
def get_hash(self):
return self.hash_value
# Example usage
zobrist = ZobristHashing(10)
zobrist.update(3, 0)
zobrist.update(7, 1)
print(f"Hash Value: {zobrist.get_hash()}")