結果

問題 No.2704 L to R Graph
コンテスト
ユーザー hos.lyric
提出日時 2024-03-29 23:34:59
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 91 ms / 3,000 ms
コード長 6,233 bytes
コンパイル時間 1,458 ms
コンパイル使用メモリ 129,736 KB
実行使用メモリ 25,948 KB
最終ジャッジ日時 2024-09-30 17:04:08
合計ジャッジ時間 4,594 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 26
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


// element to erase must exist
template <class T> struct MinPQue {
  priority_queue<T, vector<T>, greater<T>> que0, que1;
  int size() const { return que0.size() - que1.size(); }
  void push(const T &t) { que0.push(t); }
  void erase(const T &t) { que1.push(t); }
  void reduce() { for (; que0.size() && que1.size() && que0.top() == que1.top(); que0.pop(), que1.pop()) {} }
  const T &top() { reduce(); return que0.top(); }
  void pop() { reduce(); que0.pop(); }
};


struct Functional {
  int n;
  vector<int> par;
  int cyclesLen;
  vector<vector<int>> cycles;
  // cycle id or -1
  vector<int> on;
  // forest
  vector<vector<int>> graph;
  // root
  vector<int> rs;
  Functional() {}
  Functional(const vector<int> &par_) : par(par_) {
    n = par.size();
    cycles.clear();
    vector<int> vis(n, -1);
    for (int s = 0; s < n; ++s) {
      int u = s;
      for (; !~vis[u]; u = par[u]) {
        vis[u] = s;
      }
      if (vis[u] == s) {
        vector<int> cycle;
        for (int v = u; ; ) {
          cycle.push_back(v);
          if ((v = par[v]) == u) break;
        }
        cycles.push_back(cycle);
      }
    }
    cyclesLen = cycles.size();
    on.assign(n, -1);
    for (int k = 0; k < cyclesLen; ++k) {
      for (const int u : cycles[k]) {
        on[u] = k;
      }
    }
    graph.assign(n, {});
    for (int u = 0; u < n; ++u) if (!~on[u]) {
      graph[par[u]].push_back(u);
    }
    rs.assign(n, -1);
    
    zeit = 0;
    dis.assign(n, -1);
    fin.assign(n, -1);
    dep.assign(n, -1);
    
    for (int u = 0; u < n; ++u) if (~on[u]) {
      dep[u] = 0;
      dfs(u, u);
    }
  }
  void dfs(int u, int r) {
    dis[u] = zeit++;
    rs[u] = r;
    for (const int v : graph[u]) {
      dep[v] = dep[u] + 1;
      dfs(v, r);
    }
    fin[u] = zeit;
  }
  
  int zeit;
  vector<int> dis, fin, dep;
};


constexpr int INF = 1001001001;

int N, L, R;
vector<int> P;
int Q;
vector<int> S, T;

int main() {
  for (; ~scanf("%d%d%d", &N, &L, &R); ) {
    P.resize(N);
    for (int u = 0; u < N; ++u) {
      scanf("%d", &P[u]);
      --P[u];
    }
    scanf("%d", &Q);
    S.resize(Q);
    T.resize(Q);
    for (int q = 0; q < Q; ++q) {
      scanf("%d%d", &S[q], &T[q]);
      --S[q];
      --T[q];
    }
    
    const Functional F(P);
// cerr<<"cycles = "<<F.cycles<<endl;
    
    const int K = F.cyclesLen;
    vector<int> freq(K, 0);
    for (int u = 0; u < N; ++u) {
      ++freq[F.on[F.rs[u]]];
    }
    
    vector<int> ns(K + 1), ms(K + 1);
    vector<vector<int>> cost(K + 1), costSuf(K + 1);
    for (int k = 0; k <= K; ++k) {
      int &n = ns[k];
      int &m = ms[k];
      if (k == K) {
        n = N;
        m = 1;
      } else {
        n = freq[k];
        m = F.cycles[k].size();
      }
      vector<vector<int>> addss(n + m + 1), remss(n + m + 1);
      for (Int x = 0; x <= n + m; ++x) {
        // [0, n)
        {
          Int l = L * x, r = R * x;
          chmin<Int>(r, n - 1);
          if (l <= r) {
            addss[l].push_back(x);
            remss[r + 1].push_back(x);
          }
        }
        // [n, n + m)
        {
          Int l = L * x, r = R * x;
          chmax<Int>(l, n);
          if (l <= r) {
            if (r - l >= m - 1) {
              addss[n].push_back(x);
              remss[n + m].push_back(x);
            } else {
              const Int a = (l - n) % m;
              const Int b = (a + (r - l)) % m;
              if (a <= b) {
                addss[n + a].push_back(x);
                remss[n + b + 1].push_back(x);
              } else {
                addss[n + a].push_back(x);
                remss[n + m].push_back(x);
                addss[n].push_back(x);
                remss[n + b + 1].push_back(x);
              }
            }
          }
        }
      }
      MinPQue<int> que;
      que.push(INF);
      cost[k].assign(n + m, INF);
      for (int d = 0; d < n + m; ++d) {
        for (const int x : addss[d]) que.push(x);
        for (const int x : remss[d]) que.erase(x);
        cost[k][d] = que.top();
      }
      costSuf[k] = cost[k];
      for (int d = n; --d >= 0; ) {
        chmin(costSuf[k][d], costSuf[k][d + m]);
      }
    }
/*
cerr<<"ns = "<<ns<<endl;
cerr<<"ms = "<<ms<<endl;
cerr<<"cost = "<<cost<<endl;
//*/
    
    vector<int> ls(N, -1);
    for (int k = 0; k < K; ++k) {
      for (int l = 0; l < (int)F.cycles[k].size(); ++l) {
        ls[F.cycles[k][l]] = l;
      }
    }
    
    for (int q = 0; q < Q; ++q) {
      const int s = S[q], t = T[q];
      const int k = F.on[t];
      int ans = INF;
      if (~k) {
        if (F.on[F.rs[s]] == k) {
          int d = ls[t] - ls[F.rs[s]];
          if (d < 0) d += ms[k];
          d += F.dep[s];
// cerr<<"s = "<<s<<", t = "<<t<<", k = "<<k<<", d = "<<d<<endl;
          ans = costSuf[k][d];
        }
      } else {
        if (F.dis[t] <= F.dis[s] && F.dis[s] < F.fin[t]) {
          ans = cost[K][F.dep[s] - F.dep[t]];
        }
      }
      printf("%d\n", (ans < INF) ? ans : -1);
    }
  }
  return 0;
}
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