hello-algo/codes/python/chapter_searching/hashing_search.py

50 lines
1.4 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

"""
File: hashing_search.py
Created Time: 2022-11-26
Author: timi (xisunyy@163.com)
"""
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from modules import *
def hashing_search_array(mapp: dict[int, int], target: int) -> int:
"""哈希查找(数组)"""
# 哈希表的 key: 目标元素value: 索引
# 若哈希表中无此 key ,返回 -1
return mapp.get(target, -1)
def hashing_search_linkedlist(
mapp: dict[int, ListNode], target: int
) -> ListNode | None:
"""哈希查找(链表)"""
# 哈希表的 key: 目标元素value: 节点对象
# 若哈希表中无此 key ,返回 None
return mapp.get(target, None)
"""Driver Code"""
if __name__ == "__main__":
target = 3
# 哈希查找(数组)
nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8]
# 初始化哈希表
map0 = dict[int, int]()
for i in range(len(nums)):
map0[nums[i]] = i # key: 元素value: 索引
index: int = hashing_search_array(map0, target)
print("目标元素 3 的索引 =", index)
# 哈希查找(链表)
head: ListNode = list_to_linked_list(nums)
# 初始化哈希表
map1 = dict[int, ListNode]()
while head:
map1[head.val] = head # key: 节点值value: 节点
head = head.next
node: ListNode = hashing_search_linkedlist(map1, target)
print("目标节点值 3 的对应节点对象为", node)