力扣——位运算

python 复制代码

class Solution:
    def smallestNumber(self, n: int) -> int:
        return (1 << n.bit_length()) - 1

python 复制代码

class Solution:
    def minChanges(self, n: int, k: int) -> int:
        return -1 if n & k != k else (n ^ k).bit_count()

python 复制代码

class Solution:
    def sortByBits(self, arr: List[int]) -> List[int]:
        return sorted(arr, key=lambda x: (x.bit_count(), x))

python 复制代码

class Solution:
    def hammingDistance(self, x: int, y: int) -> int:
        return bin(x ^ y).count('1')

python 复制代码

class Solution:
    def minBitFlips(self, start: int, goal: int) -> int:
        # return bin(start ^ goal) .count('1')
        return (start ^ goal).bit_count()

python 复制代码

class Solution:
    def numberOfSteps(self, num: int) -> int:
        return num.bit_length() + num.bit_count() - 1 if num else 0

python 复制代码

class Solution:
    def findComplement(self, num: int) -> int:
        return num ^ ((1 << num.bit_length()) - 1)

python 复制代码

class Solution:
    def bitwiseComplement(self, n: int) -> int:
        Nbit = bin(n)
        return 2**len(Nbit[2:]) - 1 - n

python 复制代码

idx_map = {1<<i:i for i in range(30)}
class Solution:
    def binaryGap(self, n: int) -> int:
        def lowbit(x):
            return x & (-x)

        last, ans = inf, 0
        while n:
            n -= (cur := lowbit(n))
            ans, last = max(ans, idx_map[cur] - last), idx_map[cur]
        return ans

python 复制代码

class Solution:
    def hasAlternatingBits(self, n: int) -> bool:
        return not (a := n ^ (n >> 1)) & (a + 1)

python 复制代码

class Solution:
    def xorOperation(self, n: int, start: int) -> int:
        xor_n = lambda n: (n, 1, n + 1, 0)[n % 4]
        a = start // 2
        b = n & start & 1  
        return (xor_n(a + n - 1) ^ xor_n(a - 1)) * 2 + b