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| class Node():
__slots__ = 'children', 'cnt'
def __init__(self):
self.children = [None, None]
self.cnt = 0
class Trie():
HIGH_BIT = 19
def __init__(self):
self.root = Node()
def insert(self, val: int) -> None:
cur = self.root
for i in range(Trie.HIGH_BIT, -1, -1):
bit = (val >> i) & 1
if cur.children[bit] is None:
cur.children[bit] = Node()
cur = cur.children[bit]
cur.cnt += 1
return cur
def remove(self, val: int) -> None:
cur = self.root
for i in range(Trie.HIGH_BIT, -1, -1):
cur = cur.children[(val >> i) & 1]
cur.cnt -= 1
return cur
def max_xor(self, val: int) -> int:
cur = self.root
ans = 0
for i in range(Trie.HIGH_BIT, -1, -1):
bit = (val >> i) & 1
if cur.children[bit ^ 1] and cur.children[bit ^ 1].cnt:
ans |= 1 << i
bit ^= 1
cur = cur.children[bit]
return ans
class Solution:
def maximumStrongPairXor(self, nums: List[int]) -> int:
root = Trie()
nums.sort()
n = len(nums)
ret = left = 0
for y in nums:
root.insert(y)
while nums[left] * 2 < y:
root.remove(nums[left])
left += 1
ret = max(ret, root.max_xor(y))
return ret
|