2997. Make an array or harmony K The minimum number of operations

topic：

Thought：

1. firstBit operation有三个特性：
   1. Any number and0Different or operational，The result is still the original number，Right now a XOR 0 = a。
   2. Any number and自身Different or operational，turn out0，Right now a XOR a = 0。
   3. Different or operations meet the law of exchange and binding。

a = 0b1001
b = 0b0110
bin(a ^ b)

'0b1111'

first，We need to calculate the array nums All elements of all elements，Be remembered xor_sum。Our goal is to make some positions to make xor_sum equal k。

then，We can consider xor_sum XOR k the result of。Due to the characteristics of different or computing，The difference in any position will cause the bit in the result to be1。this means，We need to change xor_sum and k All different places in binary representation。

if xor_sum = 1010，k = 0011，So xor_sum XOR k = 1001。We need to change第一位and第四位来让 xor_sum become k。

That is numsHeterogeneityand kValue, in1The number is the number that needs to be converted。can watch0x3fSolution

Code：

I am

class Solution:
    def minOperations(self, nums: List[int], k: int) -> int:
        xor_sum = 0
        for num in nums:
            xor_sum ^= num

        xor_diff = xor_sum ^ k
        operations = 0

        # Calculate the digits that need to be changed
        while xor_diff:
            operations += xor_diff & 1
            xor_diff >>= 1

        return operations

0x3f

func minOperations(nums []int, k int) int {
	for _, x := range nums {
		k ^= x
	}
	return bits.OnesCount(uint(k))
}