oj.uz

Submission #679893

# Submission time Handle Problem Language Result Execution time Memory
679893 2023-01-09T15:35:21 Z peijar Building Bridges (CEOI17_building) C++17
100 / 100
 49 ms 10568 KB 
#include <bits/stdc++.h>
#define int long long
using namespace std;

namespace std {
template <typename T> ostream &operator<<(ostream &out, const vector<T> &vec) {
  out << "[";
  for (int i = 0; i < (int)vec.size(); ++i) {
    out << vec[i];
    if (i + 1 < (int)vec.size())
      out << ", ";
  }
  return out << "]";
}
} // namespace std

void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
  cout << ' ' << H;
  dbg_out(T...);
}

#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

struct Line {
  mutable int k, m, p;
  bool operator<(const Line &o) const { return k < o.k; }
  bool operator<(int x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
  // (for doubles, use inf = 1/.0, div(a,b) = a/b)
  static const int inf = LLONG_MAX;
  int div(int a, int b) { // floored division
    return a / b - ((a ^ b) < 0 && a % b);
  }
  bool isect(iterator x, iterator y) {
    if (y == end())
      return x->p = inf, 0;
    if (x->k == y->k)
      x->p = x->m > y->m ? inf : -inf;
    else
      x->p = div(y->m - x->m, x->k - y->k);
    return x->p >= y->p;
  }
  void add(int k, int m) {
    k *= -1, m *= -1;
    auto z = insert({k, m, 0}), y = z++, x = y;
    while (isect(y, z))
      z = erase(z);
    if (x != begin() && isect(--x, y))
      isect(x, y = erase(y));
    while ((y = x) != begin() && (--x)->p >= y->p)
      isect(x, erase(y));
  }
  int query(int x) {
    assert(!empty());
    auto l = *lower_bound(x);
    return -(l.k * x + l.m);
  }
};

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  int N;
  cin >> N;
  vector<int> h(N), w(N);
  vector<int> pref(N + 1);
  for (int &x : h)
    cin >> x;
  for (int i = 0; i < N; ++i) {
    cin >> w[i];
    pref[i + 1] = pref[i] + w[i];
  }

  dbg(pref);

  LineContainer lc;
  lc.add(-2 * h[0], h[0] * h[0] - pref[1]);
  vector<int> dp(N);
  for (int i = 1; i < N; ++i) {
    int valMin = lc.query(h[i]);
    dbg(i, valMin, h[i]);
    dp[i] = h[i] * h[i] + pref[i] + valMin;
    lc.add(-2 * h[i], h[i] * h[i] + dp[i] - pref[i + 1]);
  }
  cout << dp[N - 1] << endl;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 40 ms 4464 KB Output is correct
2 Correct 38 ms 4548 KB Output is correct
3 Correct 36 ms 4556 KB Output is correct
4 Correct 32 ms 4344 KB Output is correct
5 Correct 34 ms 5488 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 40 ms 4464 KB Output is correct
7 Correct 38 ms 4548 KB Output is correct
8 Correct 36 ms 4556 KB Output is correct
9 Correct 32 ms 4344 KB Output is correct
10 Correct 34 ms 5488 KB Output is correct
11 Correct 36 ms 4592 KB Output is correct
12 Correct 38 ms 4456 KB Output is correct
13 Correct 29 ms 4468 KB Output is correct
14 Correct 37 ms 4684 KB Output is correct
15 Correct 49 ms 10568 KB Output is correct
16 Correct 33 ms 5580 KB Output is correct
17 Correct 20 ms 4448 KB Output is correct
18 Correct 19 ms 4436 KB Output is correct