nlogn神秘做法70pts求教

#include <bits/stdc++.h>
using namespace std;
int n,k,a[500005],qzh[500005],tt;
vector<int> ve[1500000];
int main(){
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		qzh[i]=qzh[i-1]^a[i];
	}
	for(int i=1;i<=n;i++){
		ve[qzh[i]].push_back(i);
	}
	int pl=-1;
	ve[0].push_back(0);
	for(int i=1;i<=n;i++){
		int noww=qzh[i]^k;
		if(ve[noww].size()==0) continue;
		int p=upper_bound(ve[noww].begin(),ve[noww].end(),i)-ve[noww].begin()-1;
		if(p<0) continue;
//		cout<<'x'<<endl;
//		cout<<'y'<<endl;
		if(ve[noww][p]>=pl){
//			cout<<'z'<<endl;
			pl=i;
			tt++;
		}
	}
	cout<<tt<<endl;
	return 0;
}