hello-algo/codes/python/chapter_searching/hashing_search.py
krahets 932d14644d Polish the content
Polish the chapter preface, introduction and complexity anlysis
2023-08-08 23:16:33 +08:00

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"""
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(hmap: 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 hmap.get(target, -1)
def hashing_search_linkedlist(
hmap: 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 hmap.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)