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Complement of Base 10 Integer

Created

2022/01/06 13:18

문제 번호

1009

카테고리

Bit Manipulation

Complement of Base 10 Integer - LeetCode

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.

https://leetcode.com/problems/complement-of-base-10-integer/

Code

제출 날짜	시간	메모리
2021/01/06	0 ms	2 MB

// 1009. Complement of Base 10 Integer
//
// https://leetcode.com/problems/complement-of-base-10-integer/

// bits package has been used to call Len function.
import (
	"math/bits"
)

// bitwiseComplement function finds the number which is the complement of given input.
// Goal is to make the number 0000...101 to 0000...010.
// Find the length of the n's bit and shift the all bits 1 with the length.
// Then 1111...111 will be 1111...000 which is the mask.
// The answer can be made with that mask by xor operation.
func bitwiseComplement(n int) int {
	if n == 0 {
		return 1
	}
	return (1<<bits.Len(uint(n)) - 1) ^ n
}
Go
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