func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long bl_size = 320;   int n, m;   long long k;   long long res;   long long a[100005];   unordered_map<long long, long long> cnt;   struct Query {     int l, r, id;     bool operator<(Query other) const {       if (l / bl_size != other.l / bl_size)         return l < other.l;       else         return (l / bl_size & 1) ? (r < other.r) : (r > other.r);     }   };   void add(long long x) {     long long y = x ^ k;     res += cnt[y];     cnt[x]++;   }   void rem(long long x) {     long long y = x ^ k;     if (y != x)       res -= (cnt[y]);     else       res -= (cnt[y] - 1);     cnt[x]--;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     scanf( %d%d%d , &n, &m, &k);     long long prev[n + 10];     prev[0] = 0;     for (int i = 1; i <= n; i++) scanf( %d , &a[i]), prev[i] = prev[i - 1] ^ a[i];     Query q[100005];     for (int i = 1; i <= m; i++) {       scanf( %d%d , &q[i].l, &q[i].r);       q[i].l--;       q[i].id = i;     }     sort(q + 1, q + n + 1);     res = 0;     long long ans[m + 10];     int cur_l = 0, cur_r = -1;     for (int i = 1; i <= m; i++) {       while (cur_l > q[i].l) {         cur_l--;         add(prev[cur_l]);       }       while (cur_l < q[i].l) {         rem(prev[cur_l]);         cur_l++;       }       while (cur_r > q[i].r) {         rem(prev[cur_r]);         cur_r--;       }       while (cur_r < q[i].r) {         cur_r++;         add(prev[cur_r]);       }       ans[q[i].id] = res;     }     for (int i = 1; i <= m; i++) cout << ans[i] << endl;   }   