Submission #903922

#	Time	Username	Problem	Language	Result	Execution time	Memory
903922		LucaLucaM	Intergalactic ship (IZhO19_xorsum)	C++17	0 / 100	2053 ms	1776 KiB

xorsum

#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
#include <cstring>
#warning That's the baby, that's not my baby

typedef long long ll;

const int mod = 1e9 + 7;

struct Update {
  int l, r, x;
};

int power(int a, int b) {
  int p = 1;
  while (b) {
    if (b & 1) {
      p = (ll) p * a % mod;
    }
    a = (ll) a * a % mod;
    b >>= 1;
  }
  return p;
}

int solve(std::vector<int> a) {
  int n = (int) a.size();
  ll ret = 0;
  for (int i = 0; i < n; i++) {
    ret += (ll) a[i] * a[i] % mod * (i + 1) * (n - i) % mod;
    for (int j = i + 1; j < n; j++) {
      ret += (ll) 2 * a[i] * a[j] % mod * (i + 1) * (n - j) % mod;
    }
  }
  return ret % mod;
}

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(0);

  int n;
  std::cin >> n;
  std::vector<int> a(n);
  for (auto &x : a) {
    std::cin >> x;
  }

  int q;
  std::cin >> q;

  if (q == 0) {
    std::cout << solve(a);
    return 0;
  }

  std::vector<Update> Q(q);

  for (auto &[l, r, x] : Q) {
    std::cin >> l >> r >> x;
    --l, --r;
  }

  ll answer = 0;

  for (int mask = 0; mask < (1 << q); mask++) {
    std::vector<int> b = a;
    for (int i = 0; i < q; i++) {
      if (mask & (1 << i)) {
        for (int k = Q[i].l; k <= Q[i].r; k++) {
          b[k] ^= Q[i].x;
        }
      }
      answer += solve(b);
    }
  }

  std::cout << answer % mod;


  return 0;
}

Compilation message (stderr)

xorsum.cpp:6:2: warning: #warning That's the baby, that's not my baby [-Wcpp]
    6 | #warning That's the baby, that's not my baby
      |  ^~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 5
• Subtask 3: 0 / 6
• Subtask 4: 0 / 9
• Subtask 5: 0 / 8
• Subtask 6: 0 / 11
• Subtask 7: 0 / 19
• Subtask 8: 0 / 30
• Subtask 9: 0 / 8