Is Complement of Base 10 Integer easy or hard?

Complement of Base 10 Integer is categorized as an Easy problem on LeetCode with an acceptance rate above 60%. The main challenge is understanding why a mask is required instead of using the bitwise NOT operator directly.

Complement of Base 10 Integer Python/Java solution

In Python or Java, compute the bit length of n, create a mask like (1 << k) - 1, and return mask ^ n. Python also provides n.bit_length() to determine k directly. Java implementations typically use a loop or shifting to determine the mask size.

How to solve Complement of Base 10 Integer in O(log n)?

Compute the number of bits in n and build a mask containing only 1s for those positions. A common formula is mask = (1 << k) - 1 where k is the bit length. The complement is then mask ^ n, which flips every bit within the mask range.

What is the best approach for Complement of Base 10 Integer?

The most efficient approach uses bit manipulation with a mask. First compute a mask with all bits set to 1 for the length of the number, such as (1 << k) - 1 where k is the number of bits in n. Then return mask XOR n to flip only the relevant bits. This runs in O(log n) time and O(1) space.

Is Complement of Base 10 Integer asked at Google/Amazon/Meta?

Bit manipulation problems similar to this appear in interviews at companies like Google, Amazon, and Meta. They are often used to test understanding of binary representation, bit masks, and XOR operations. The difficulty is easy but the concept appears frequently in screening rounds.

What data structure is used in Complement of Base 10 Integer?

No complex data structure is required. The problem relies purely on bitwise operations such as XOR, shifts, and masks. Some implementations use arithmetic operations to extract bits, but the core concept belongs to bit manipulation.

What is the time complexity of Complement of Base 10 Integer?

The time complexity is O(log n) because the algorithm processes the binary length of the number. Whether you build a mask or iterate through bits using division or shifts, the number of steps equals the number of bits in n. Space complexity is O(1).

Description Hints 1 Solution Video 8:13

1009. Complement of Base 10 Integer

Q: How to solve Complement of Base 10 Integer in O(log n)?

Compute the number of bits in n and build a mask containing only 1s for those positions. A common formula is mask = (1 << k) - 1 where k is the bit length. The complement is then mask ^ n, which flips every bit within the mask range.

Q: What is the best approach for Complement of Base 10 Integer?

The most efficient approach uses bit manipulation with a mask. First compute a mask with all bits set to 1 for the length of the number, such as (1 << k) - 1 where k is the number of bits in n. Then return mask XOR n to flip only the relevant bits. This runs in O(log n) time and O(1) space.

Q: Is Complement of Base 10 Integer asked at Google/Amazon/Meta?

Bit manipulation problems similar to this appear in interviews at companies like Google, Amazon, and Meta. They are often used to test understanding of binary representation, bit masks, and XOR operations. The difficulty is easy but the concept appears frequently in screening rounds.

Q: What data structure is used in Complement of Base 10 Integer?

No complex data structure is required. The problem relies purely on bitwise operations such as XOR, shifts, and masks. Some implementations use arithmetic operations to extract bits, but the core concept belongs to bit manipulation.

Q: What is the time complexity of Complement of Base 10 Integer?

The time complexity is O(log n) because the algorithm processes the binary length of the number. Whether you build a mask or iterate through bits using division or shifts, the number of steps equals the number of bits in n. Space complexity is O(1).

Easy63.3% acceptance5 companies

The complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.

For example, The integer 5 is "101" in binary and its complement is "010" which is the integer 2.

Given an integer n, return its complement.

Example 1:

Input: n = 5
Output: 2
Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10.

Example 2:

Input: n = 7
Output: 0
Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.

Example 3:

Input: n = 10
Output: 5
Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.

Constraints:

0 <= n < 10⁹

Note: This question is the same as 476: https://leetcode.com/problems/number-complement/

Asked at 5 companies

Cloudera Bloomberg

Google Amazon Meta

Topics

Bit Manipulation

Hints open one at a time

Hint 1

A binary number plus its complement will equal 111....111 in binary. Also, N = 0 is a corner case.

8:13

Still stuck?Read 3 approaches, or watch a walkthrough.

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1class Solution:
2    def bitwiseComplement(self, n: int) -> int:
3        

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