题目 #

You are given a positive integer n.

Let even denote the number of even indices in the binary representation of n (0-indexed) with value 1.

Let odd denote the number of odd indices in the binary representation of n (0-indexed) with value 1.

Return an integer array answer where answer = [even, odd].

Example 1:

Input: n = 17
Output: [2,0]
Explanation: The binary representation of 17 is 10001.
It contains 1 on the 0th and 4th indices.
There are 2 even and 0 odd indices.

Example 2:

Input: n = 2
Output: [0,1]
Explanation: The binary representation of 2 is 10.
It contains 1 on the 1st index.
There are 0 even and 1 odd indices.
``` 

Constraints:

- 1 <= n <= 1000

# 思路1

## 分析

- 照着做

## 代码

```go
func evenOddBit(n int) []int {
	res := []int{0, 0}
	isOdd := false
	for n > 0 {
		if n&0x01 == 1 {
			if isOdd {
				res[1]++
			} else {
				res[0]++
			}
		}
		n >>= 1
		isOdd = !isOdd
	}
	return res
}