Submission #1087199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087199		avighna	Lasers (NOI19_lasers)	C++17	100 / 100	656 ms	72368 KiB

lasers

#include <bits/stdc++.h>

typedef long long ll;

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

  ll l, r;
  std::cin >> l >> r;
  std::priority_queue<std::pair<ll, ll>, std::vector<std::pair<ll, ll>>,
                      std::greater<>>
      pq;
  std::vector<ll> left(r), sum(r);
  std::vector<std::vector<ll>> rows(r);
  std::multiset<ll> st;
  // x blocks from right ==> l - x + 1 from left
  auto f = [&](ll cnt) { return l - (sum[cnt] - left[cnt]) + 1; };
  for (ll cnt = 0; cnt < r; ++cnt) {
    auto &v = rows[cnt];
    ll len;
    std::cin >> len;
    v.resize(len);
    for (auto &i : v) {
      std::cin >> i;
    }
    std::reverse(v.begin(), v.end());
    sum[cnt] = std::accumulate(v.begin(), v.end(), 0LL);
    pq.push({left[cnt] + v.back(), cnt});
    v.pop_back();
    st.insert(f(cnt));
  }

  auto get = [](ll l, ll r, ll c) {
    if (r <= c) {
      return r - l + 1;
    }
    if (l > c) {
      return 0LL;
    }
    return c - l + 1;
  };

  ll ans = l;
  for (ll _i = 1; _i <= l; ++_i) {
    while (!pq.empty() and pq.top().first < _i) {
      auto [l, i] = pq.top();
      pq.pop();
      st.erase(st.find(f(i)));
      left[i] = l;
      st.insert(f(i));
      if (!rows[i].empty()) {
        pq.push({left[i] + rows[i].back(), i});
        rows[i].pop_back();
      }
    }
    ll beg = _i, end = !pq.empty() ? pq.top().first : l;
    ans -= get(beg + 1, end + 1, *st.begin());
    _i = end;
  }
  std::cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 20 / 20
• Subtask 4: 21 / 21
• Subtask 5: 22 / 22
• Subtask 6: 13 / 13