Submission #492252

#	Time	Username	Problem	Language	Result	Execution time	Memory
492252		cuiaoxiang	Fireworks (APIO16_fireworks)	C++17	100 / 100	264 ms	94404 KiB

fireworks

#define LOCAL
#define _USE_MATH_DEFINES
#include <array>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>
#include <random>
#include <ctime>

using namespace std;

template <typename A, typename B>
ostream& operator <<(ostream& out, const pair<A, B>& a) {
  out << "(" << a.first << "," << a.second << ")";
  return out;
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const multiset<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
#ifdef LOCAL
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
#else
#define trace(...) 42
#endif
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

template <class T> auto vect(const T& v, int n) { return vector<T>(n, v); }
template <class T, class... D> auto vect(const T& v, int n, D... m) {
  return vector<decltype(vect(v, m...))>(n, vect(v, m...));
}

using int64 = long long;
using int128 = __int128_t;
using ii = pair<int, int>;
#define SZ(x) (int)((x).size())
template <typename T> static constexpr T inf = numeric_limits<T>::max() / 2;
const int MOD = 1e9 + 7;
// const int MOD = 998244353;
// mt19937 mrand(random_device{}());
// int rnd(int x) { return mrand() % x; }
mt19937_64 mrand(random_device{}());
int64 rnd(int64 x) { return mrand() % x; }
template <class T> void out(const vector<T>& a) { for (int i = 0; i < SZ(a); ++i) cout << a[i] << " \n"[i + 1 == SZ(a)]; }
template <class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template <class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
template <class T> void dedup(vector<T>& v) { sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); }
void add_mod(int& x, int y) { x += y; if (x >= MOD) x -= MOD; }
void sub_mod(int& x, int y) { x += MOD - y; if (x >= MOD) x -= MOD; }

struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  };
} fast_ios_;

const int N = 3e5 + 10;
vector<ii> a[N];

template <typename T>
struct slope_trick {
  T min_f;
  priority_queue<T, vector<T>, less<>> L;
  priority_queue<T, vector<T>, greater<>> R;
  T add_l, add_r;

  void pushR(const T& x) {
    R.push(x - add_r);
  }
  T topR() const {
    if (R.empty()) return inf<T>;
    return R.top() + add_r;
  }
  T popR() {
    T ret = topR();
    if (!R.empty()) R.pop();
    return ret;
  }
  void pushL(const T& x) {
    L.push(x - add_l);
  }
  T topL() const {
    if (L.empty()) return -inf<T>;
    return L.top() + add_l;
  }
  T popL() {
    T ret = topL();
    if (!L.empty()) L.pop();
    return ret;
  }
  size_t size() { return L.size() + R.size(); }
  slope_trick() : min_f(0), add_l(0), add_r(0) {}

  // f(x) += a
  void add_all(const T& a) {
    min_f += a;
  }
  // add \_
  // f(x) += max(a - x, 0)
  void add_a_minus_x(const T& a) {
    min_f += max(T(0), a - topR());
    pushR(a);
    pushL(popR());
  }
  // add _/
  // f(x) += max(x - a, 0)
  void add_x_minus_a(const T& a) {
    min_f += max(T(0), topL() - a);
    pushL(a);
    pushR(popL());
  }
  // add \/
  // f(x) += abs(x - a)
  void add_abs(const T& a) {
    add_a_minus_x(a);
    add_x_minus_a(a);
  }
  // \/ -> \_
  // f_new(x) = min f(y) (y <= x)
  void clear_right() {
    while (!R.empty()) R.pop();
  }
  // \/ -> _/
  // f_new(x) = min f(y) (y >= x)
  void clear_left() {
    while (!L.empty()) L.pop();
  }
  // \/ -> \_/
  // f_new(x) = min f(y) (x-b <= y <= x-a)
  void expand(const T& a, const T& b) {
    assert(a <= b);
    add_l += a;
    add_r += b;
  }
  // \/. -> .\/
  // f_new(x) = f(x - a)
  void shift(const T& a) {
    expand(a, a);
  }
  // L, R will be emptied.
  T get(const T& x) {
    T ret = min_f;
    while (!L.empty()) ret += max(T(0), popL() - x);
    while (!R.empty()) ret += max(T(0), x - popR());
    return ret;
  }
  void merge(slope_trick& other) {
    if (other.size() > size()) {
      swap(other.L, L);
      swap(other.R, R);
      swap(other.add_l, add_l);
      swap(other.add_r, add_r);
      swap(other.min_f, min_f);
    }
    while (!other.R.empty()) add_x_minus_a(other.popR());
    while (!other.L.empty()) add_a_minus_x(other.popL());
    min_f += other.min_f;
  }

};

slope_trick<int64> st[N];
void dfs(int u, int parent) {
  int cnt = 0;
  for (auto& [v, w] : a[u]) {
    if (v == parent) continue;
    dfs(v, u);
    ++cnt;
    int64 topR = st[v].topR() + w;
    st[v].clear_right();
    st[v].pushR(topR);
    int64 topL = st[v].topL() + w;
    st[v].popL();
    st[v].pushL(topL);

    st[u].merge(st[v]);
  }
  if (cnt == 0) st[u].add_abs(0);
}

int main() {
  int n, m;
  cin >> n >> m;
  n += m;

  for (int i = 1; i < n; ++i) {
    int p, c;
    cin >> p >> c;
    --p;
    a[p].push_back({i, c});
  }

  dfs(0, -1);
  cout << st[0].min_f << '\n';

  return 0;
}

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