다양한 방법으로 해시맵 구현

문제 설명: get, set 및 remove 메소드를 사용하여 해시 맵을 구현하십시오.

난이도: 쉬움

테스트 케이스

연산

시간 및 공간 복잡성

암호

class Item(object):
    def __init__(self, key, value):
        self.key = key
        self.value = value


class HashTable(object):
    def __init__(self, size):
        self.size = size
        self.table = [[] for _ in range(self.size)]

    def hashFunction(self, key):
        return key % self.size

    def set(self, key, value):
        hashIndex = self.hashFunction(key)
        for item in self.table[hashIndex]:
            if item.key == key:
                item.value = value
                return
        self.table[hashIndex].append(Item(key, value))

    def get(self, key):
        hashIndex = self.hashFunction(key)
        for item in self.table[hashIndex]:
            if item.key == key:
                return item.value
        raise KeyError('Key not found')

    def remove(self, key):
        hashIndex = self.hashFunction(key)
        for index, item in enumerate(self.table[hashIndex]):
            if item.key == key:
                del self.table[hashIndex][index]
                return
        raise KeyError('Key not found')

단위 테스트

import unittest
from hashmap import HashTable


class TestHashMap(unittest.TestCase):

    def test_end_to_end(self):
        hash_table = HashTable(10)

        print("Test: get on an empty hash table index")
        self.assertRaises(KeyError, hash_table.get, 0)

        print("Test: set on an empty hash table index")
        hash_table.set(0, 'first')
        self.assertEqual(hash_table.get(0), 'first')
        hash_table.set(1, 'second')
        self.assertEqual(hash_table.get(1), 'second')

        print("Test: set on a non empty hash table index")
        hash_table.set(10, 'third')
        self.assertEqual(hash_table.get(0), 'first')
        self.assertEqual(hash_table.get(10), 'third')

        print("Test: set on a key that already exists")
        hash_table.set(10, 'fourth')
        self.assertEqual(hash_table.get(0), 'first')
        self.assertEqual(hash_table.get(10), 'fourth')

        print("Test: remove on a key that already exists")
        hash_table.remove(10)
        self.assertEqual(hash_table.get(0), 'first')
        self.assertRaises(KeyError, hash_table.get, 10)

        print("Test: remove on a key that doesn't exist")
        self.assertRaises(KeyError, hash_table.remove, -1)

        print('Success: test_end_to_end')


def main():
    test = TestHashMap()
    test.test_end_to_end()


if __name__ == "__main__":
    main()

해피코딩!! 🌟