Submission #262667

#	Time	Username	Problem	Language	Result	Execution time	Memory
262667		KoD	Fireworks (APIO16_fireworks)	C++11	26 / 100	32 ms	8832 KiB

fireworks

/**
 * @title Template
 */

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>
#include <cassert>
#include <iomanip>


template <class T, class U>
bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

template <class T, class U>
bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

/**
 * @title Chmin/Chmax
 */


class range {
public:
  class iterator {
  private:
    int64_t M_position;

  public:
    iterator(int64_t position) noexcept: M_position(position) { }
    void operator ++ () noexcept { ++M_position; }
    bool operator != (iterator other) const noexcept { return M_position != other.M_position; }
    int64_t operator * () const noexcept { return M_position; }

  };

  class reverse_iterator {
  private:
    int64_t M_position;
  
  public:
    reverse_iterator(int64_t position) noexcept: M_position(position) { }
    void operator ++ () noexcept { --M_position; }
    bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; }
    int64_t operator * () const noexcept { return M_position; }

  };
  
private:
  const iterator M_first, M_last;

public:
  range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { }
  iterator begin() const noexcept { return M_first; }
  iterator end() const noexcept { return M_last; }
  reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } 
  reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } 

};

/**
 * @title Range
 */

#include <type_traits>
#include <iterator>

template <class T>
class rev_impl {
public:
  using iterator = decltype(std::declval<T>().rbegin());

private:
  const iterator M_begin;
  const iterator M_end;

public:
  rev_impl(T &&cont) noexcept: M_begin(cont.rbegin()), M_end(cont.rend()) { }
  iterator begin() const noexcept { return M_begin; }
  iterator end() const noexcept { return M_end; }

};

template <class T>
rev_impl<T> rev(T &&cont) {
  return rev_impl<T>(std::forward<T>(cont));
}

/**
 * @title Reverser
 */

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

i32 N, M, V;
std::array<i32, 300000> P, C;

struct edge_t {
  const i32 to;
  const i32 cost;
  edge_t(i32 to_, i32 cost_): to(to_), cost(cost_) { }
};

std::array<std::vector<edge_t>, 300000> graph;
std::array<std::array<i64, 301>, 300> dp;

void dfs(i32 u) {
  if (u >= N) {
    dp[u].fill(inf64);
    dp[u][0] = 0;
    return;
  }
  for (auto p: graph[u]) {
    const i32 v = p.to;
    if (v != P[u]) {
      dfs(v);
      std::array<i64, 301> next;
      next.fill(inf64);
      for (auto j: range(0, 301)) {
        for (auto k: range(0, 301 - j)) {
          chmin(next[j + k], dp[v][j] + std::abs(p.cost - k));
        }
      }
      for (auto j: range(0, 301)) {
        dp[u][j] += next[j];
      }
    }
  }
}

int main() {
  std::cin >> N >> M;
  V = N + M;
  --P[0];
  for (auto i: range(1, V)) {
    std::cin >> P[i] >> C[i];
    --P[i];
    graph[P[i]].emplace_back(i, C[i]);
    graph[i].emplace_back(P[i], C[i]);
  }
  if (N == 1) {
    std::vector<i32> vec;
    vec.reserve(M);
    for (auto i: range(N, N + M)) {
      vec.push_back(C[i]);
    }
    std::sort(vec.begin(), vec.end());
    i32 goal = vec[vec.size() / 2];
    i64 ans = 0;
    for (auto x: vec) {
      ans += std::abs(goal - x);
    }
    std::cout << ans << '\n';
  }
  else if (V <= 300) {
    dfs(0);
    i64 ans = inf64;
    for (auto j: range(0, 301)) {
      chmin(ans, dp[0][j]);
    }
    std::cout << ans << '\n';
  }
  return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45