func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize(3,  Ofast ,  inline )   using namespace std;   const long long INF(0x3f3f3f3f3f3f3f3fll);   const long long inf(0x3f3f3f3f);   template <typename T>   void read(T &res) {     bool flag = false;     char ch;     while (!isdigit(ch = getchar())) (ch ==  - ) && (flag = true);     for (res = ch - 48; isdigit(ch = getchar());          res = (res << 1) + (res << 3) + ch - 48)       ;     flag && (res = -res);   }   template <typename T>   void Out(T x) {     if (x < 0) putchar( - ), x = -x;     if (x > 9) Out(x / 10);     putchar(x % 10 +  0 );   }   long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }   long long lcm(long long a, long long b) { return a * b / gcd(a, b); }   long long pow_mod(long long x, long long n, long long mod) {     long long res = 1;     while (n) {       if (n & 1) res = res * x % mod;       x = x * x % mod;       n >>= 1;     }     return res;   }   long long fact_pow(long long n, long long p) {     long long res = 0;     while (n) {       n /= p;       res += n;     }     return res;   }   long long mult(long long a, long long b, long long p) {     a %= p;     b %= p;     long long r = 0, v = a;     while (b) {       if (b & 1) {         r += v;         if (r > p) r -= p;       }       v <<= 1;       if (v > p) v -= p;       b >>= 1;     }     return r;   }   long long quick_pow(long long a, long long b, long long p) {     long long r = 1, v = a % p;     while (b) {       if (b & 1) r = mult(r, v, p);       v = mult(v, v, p);       b >>= 1;     }     return r;   }   bool CH(long long a, long long n, long long x, long long t) {     long long r = quick_pow(a, x, n);     long long z = r;     for (long long i = 1; i <= t; i++) {       r = mult(r, r, n);       if (r == 1 && z != 1 && z != n - 1) return true;       z = r;     }     return r != 1;   }   bool Miller_Rabin(long long n) {     if (n < 2) return false;     if (n == 2) return true;     if (!(n & 1)) return false;     long long x = n - 1, t = 0;     while (!(x & 1)) {       x >>= 1;       t++;     }     srand(time(NULL));     long long o = 8;     for (long long i = 0; i < o; i++) {       long long a = rand() % (n - 1) + 1;       if (CH(a, n, x, t)) return false;     }     return true;   }   long long exgcd1(long long a, long long b, long long &x, long long &y) {     if (!b) {       x = 1, y = 0;       return a;     }     long long t = exgcd1(b, a % b, y, x);     y -= a / b * x;     return t;   }   long long get_inv(long long a, long long mod) {     long long x, y;     long long d = exgcd1(a, mod, x, y);     return d == 1 ? (x % mod + mod) % mod : -1;   }   void exgcd(long long a, long long b, long long &x, long long &y) {     if (!b) {       x = 1, y = 0;       return;     }     exgcd(b, a % b, x, y);     long long t = x;     x = y, y = t - (a / b) * y;   }   long long INV(long long a, long long b) {     long long x, y;     return exgcd(a, b, x, y), (x % b + b) % b;   }   long long crt(long long x, long long p, long long mod) {     return INV(p / mod, mod) * (p / mod) * x;   }   long long FAC(long long x, long long a, long long b) {     if (!x) return 1;     long long ans = 1;     for (long long i = 1; i <= b; i++)       if (i % a) ans *= i, ans %= b;     ans = pow_mod(ans, x / b, b);     for (long long i = 1; i <= x % b; i++)       if (i % a) ans *= i, ans %= b;     return ans * FAC(x / a, a, b) % b;   }   long long C(long long n, long long m, long long a, long long b) {     long long N = FAC(n, a, b), M = FAC(m, a, b), Z = FAC(n - m, a, b), sum = 0,               i;     for (i = n; i; i = i / a) sum += i / a;     for (i = m; i; i = i / a) sum -= i / a;     for (i = n - m; i; i = i / a) sum -= i / a;     return N * pow_mod(a, sum, b) % b * INV(M, b) % b * INV(Z, b) % b;   }   long long exlucas(long long n, long long m, long long p) {     long long t = p, ans = 0, i;     for (i = 2; i * i <= p; i++) {       long long k = 1;       while (t % i == 0) {         k *= i, t /= i;       }       ans += crt(C(n, m, i, k), p, k), ans %= p;     }     if (t > 1) ans += crt(C(n, m, t, t), p, t), ans %= p;     return ans % p;   }   const long long N = 1e6 + 10;   long long tree[N << 2];   long long n, m;   long long a[N], sum[N];   map<long long, long long> pos;   long long lowbit(long long x) { return x & (-x); }   void add(long long pos, long long val) {     while (pos <= n) {       tree[pos] ^= val;       pos += lowbit(pos);     }   }   long long get(long long pos) {     long long res = 0;     while (pos) {       res ^= tree[pos];       pos -= lowbit(pos);     }     return res;   }   long long get_sum(long long l, long long r) { return get(r) ^ get(l - 1); }   struct Q {     long long l, r, ans, id;     bool operator<(const Q &a) const { return r < a.r; }   } q[N];   bool cmp(Q a, Q b) { return a.id < b.id; }   signed main() {     std::ios::sync_with_stdio(false);     cin.tie(0), cout.tie(0);     cin >> n;     for (long long i = 1; i <= n; i++) cin >> a[i], sum[i] = sum[i - 1] ^ a[i];     cin >> m;     for (long long i = 1; i <= m; i++) cin >> q[i].l >> q[i].r, q[i].id = i;     sort(q + 1, q + 1 + m);     long long now = 1;     for (long long i = 1; i <= m; i++) {       long long l = q[i].l, r = q[i].r, id = q[i].id;       while (now <= r) {         if (pos[a[now]]) add(pos[a[now]], a[now]);         pos[a[now]] = now;         add(pos[a[now]], a[now]);         now++;       }       q[i].ans = (sum[r] ^ sum[l - 1]) ^ get_sum(l, r);     }     sort(q + 1, q + 1 + m, cmp);     for (long long i = 1; i <= m; i++) cout << q[i].ans <<   n ;     return 0;   }   