求问

#include <bits/stdc++.h>

int N, K, nums[500010], pre_xor[500010], ans, now;

int main() {
	std::cin >> N >> K;
	for (int i = 1; i <= N; i ++) 
		std::cin >> nums[i], pre_xor[i] = pre_xor[i - 1] ^ nums[i];
	
	for (int i = 1; i <= N; i ++)
		for (int j = now; j < i; j ++)
			if ((pre_xor[i] ^ pre_xor[j]) == K) {
				now = i, ans ++;
				break;
			}
	
	std::cout << ans;
	return 0;
}