E.cpp

#include<bits/stdc++.h>

using namespace std;
const int MAXN = 1e6 + 2;
struct trie{
    int cnt = 0;
    int links[2];
} b[30 * MAXN];
int pr[MAXN];

//vector <trie> b;

int cntV = 0;

void add(int x){
    int v = 0;
    b[v].cnt++;
    int bit;
    for (int i = 29; i >= 0; i--){
        bit = (x >> i) & 1;
        if (b[v].links[bit] != -1){
            v = b[v].links[bit];
            b[v].cnt++;
        }
        else{
            cntV++;
            b[v].links[bit] = cntV;
            v = cntV;
            b[v].cnt++;
            b[v].links[0] = -1;
            b[v].links[1] = -1;
        }
    }
}

int get_cnt(int x, int k){
    int ans = 0;
    int v = 0;
    int bitX, bitK;
    for (int i = 29; i >= 0; i--){
        bitX = (x >> i) & 1;
        bitK = (k >> i) & 1;

        if (bitK == 0 && bitX == 0){
            if (b[v].links[1] != -1){
                ans += b[b[v].links[1]].cnt;
            }
            if (b[v].links[0] != -1){
                v = b[v].links[0];
            }
            else{
                return ans;
            }
        }

        if (bitK == 0 && bitX == 1){
            if (b[v].links[0] != -1){
                ans += b[b[v].links[0]].cnt;
            }
            if (b[v].links[1] != -1){
                v = b[v].links[1];
            }
            else{
                return ans;
            }
        }

        if (bitK == 1){
            if (b[v].links[1 ^ bitX] != -1){
                v = b[v].links[1 ^ bitX];
            }
            else{
                return ans;
            }
        }

    }
    ans += b[v].cnt;
    return ans;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    b[0].links[0] = -1;
    b[0].links[1] = -1;

    int n, k;
    cin >> n >> k;
    int a[n + 1];

    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }
    add(0);
    long long answer = 0;
    for (int i = 1; i <= n; i++){
        pr[i] = pr[i - 1] ^ a[i];
        answer += get_cnt(pr[i], k);
        add(pr[i]);
    }
    cout << answer;

    return 0;
}