hack未过求调

#include <bits/stdc++.h>
using namespace std;
const int QWQ = 1e5 + 5;
int a[QWQ], pos[QWQ], L[QWQ], R[QWQ], n, m, k;
int block, num, cnt[QWQ], sum[QWQ], ans, q[QWQ];
struct node
{
    int l, r, id;
} w[QWQ];
bool cmp(node a, node b)
{
    if (pos[a.l] == pos[b.l])
    {
        return a.r < b.r;
    }
    return a.l < b.l;
}
void init()
{
    block = sqrt(n);
    num = n / block;
    for (int i = 1; i <= n; i++)
    {
        pos[i] = i / block + 1;
    }
    for (int i = 1; i <= num; i++)
    {
        L[i] = block * (i - 1) + 1;
        R[i] = block * i;
    }
    R[num] = n;
}
void add(int x)
{
    cnt[a[x]]++;
    ans += cnt[a[x] ^ k];
}
void del(int x)
{
    cnt[a[x]]--;
    ans -= cnt[a[x] ^ k];
}
signed main()
{
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        a[i] ^= a[i - 1];
    }
    init();
    for (int i = 1; i <= m; i++)
    {
        cin >> w[i].l >> w[i].r;
        w[i].id = i;
    }
    sort(w + 1, w + m + 1, cmp);
    int l = 0, r = 0;
    cnt[0] = 1;
    for (int i = 1; i <= m; i++)
    {
        w[i].l = w[i].l - 1;
        while (l < w[i].l)
        {
            del(l ++);
        }
        while (l > w[i].l)
        {
            add(-- l);
        }
        while (r < w[i].r)
        {
            add(++r);
        }
        while (r > w[i].r)
        {
            del(r--);
        }
        q[w[i].id] = ans;
    }
    for (int i = 1; i <= m; i++)
    {
        cout << q[i] << endl;
    }
}