oj.uz

Submission #259108

# Submission time Handle Problem Language Result Execution time Memory
259108 2020-08-07T08:17:10 Z KoD Beads and wires (APIO14_beads) C++17
13 / 100
 2 ms 640 KB 
#line 1 "main.cpp"

/**
 * @title Template
 */

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>
#include <tuple>
#include <cassert>
#include <random>

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp"

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

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

/**
 * @title Chmin/Chmax
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

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

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

  };

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

  };
  
private:
  const iterator M_first, M_last;

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

};

/**
 * @title Range
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

#include <type_traits>
#include <iterator>
#line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

template <class T>
class rev_impl {
public:
  using iterator = typename std::decay<T>::type::reverse_iterator;

private:
  const iterator M_begin;
  const iterator M_end;

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

};

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

/**
 * @title Reverser
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp"

template <class Func>
struct fix_point_impl: private Func {
  explicit constexpr fix_point_impl(Func &&func): Func(std::forward<Func>(func)) { }
  template <class... Args>
  constexpr decltype(auto) operator () (Args &&... args) const {
    return Func::operator()(*this, std::forward<Args>(args)...);
  }
};

template <class Func>
constexpr decltype(auto) fix_point(Func &&func) {
  return fix_point_impl<Func>(std::forward<Func>(func));
}

/**
 * @title Lambda Recursion
 */
#line 20 "main.cpp"

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;

struct edge_t {
  i32 to, cost;
  edge_t(i32 t, i32 c): to(t), cost(c) { }
};

std::vector<edge_t> graph[10000];
i32 root[10000], mid[10000];

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);
  i32 N;
  std::cin >> N;
  assert(N <= 10000);
  for (auto i: range(1, N)) {
    i32 u, v, c;
    std::cin >> u >> v >> c;
    --u; --v;
    graph[u].emplace_back(v, c);
    graph[v].emplace_back(u, c);
  }
  i32 ans = 0;
  std::vector<i32> cand((N + 1) / 2);
  std::iota(cand.begin(), cand.end(), 0);
  {
    std::mt19937 mt;
    std::shuffle(cand.begin(), cand.end(), mt);
  }
  for (auto src: cand) {
    fix_point([&](auto dfs, i32 u, i32 p) -> void {
      root[u] = mid[u] = 0;
      i32 max_c = -inf32;
      for (auto [v, c]: graph[u]) {
        if (v == p) continue;
        dfs(v, u);
        i32 tmp = std::max(root[v], mid[v] + c);
        root[u] += tmp;
        chmax(max_c, root[v] + c - tmp);
      }
      mid[u] = root[u] + max_c;
    })(src, -1);
    chmax(ans, root[src]);
  }
  std::cout << ans << '\n';
  return 0;
}

Compilation message

main.cpp: In function 'int main()':
main.cpp:43:13: warning: unused variable 'i' [-Wunused-variable]

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 0 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 0 ms 512 KB Output is correct

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 0 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 0 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 512 KB Output is correct
15 Correct 1 ms 512 KB Output is correct
16 Correct 1 ms 640 KB Output is correct
17 Incorrect 2 ms 640 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 0 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 0 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 512 KB Output is correct
15 Correct 1 ms 512 KB Output is correct
16 Correct 1 ms 640 KB Output is correct
17 Incorrect 2 ms 640 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 0 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 0 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 512 KB Output is correct
15 Correct 1 ms 512 KB Output is correct
16 Correct 1 ms 640 KB Output is correct
17 Incorrect 2 ms 640 KB Output isn't correct
18 Halted 0 ms 0 KB -