Submission #682625

#	Time	Username	Problem	Language	Result	Execution time	Memory
682625		peijar	Long Mansion (JOI17_long_mansion)	C++17	100 / 100	228 ms	42100 KiB

long_mansion

#include <bits/stdc++.h>
using namespace std;

inline char gc() { // like getchar()
  static char buf[1 << 16];
  static size_t bc, be;
  if (bc >= be) {
    buf[0] = 0, bc = 0;
    be = fread(buf, 1, sizeof(buf), stdin);
  }
  return buf[bc++]; // returns 0 on EOF
}

int readInt() {
  int a, c;
  while ((a = gc()) < 40)
    ;
  if (a == '-')
    return -readInt();
  while ((c = gc()) >= 48)
    a = a * 10 + c - 480;
  return a - 48;
}

string to_string(string s) { return s; }
template <typename T> string to_string(T v) {
  bool first = true;
  string res = "[";
  for (const auto &x : v) {
    if (!first)
      res += ", ";
    first = false;
    res += to_string(x);
  }
  res += "]";
  return res;
}

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

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

const int MAXN = 2e6;

int iDeb[MAXN], iFin[MAXN], seg[MAXN];
vector<int> lst;

void build(int node, int l, int r) {
  iDeb[node] = l, iFin[node] = r;
  if (l == r) {
    seg[node] = lst[l];
    return;
  }
  build(2 * node, l, (l + r) / 2);
  build(2 * node + 1, (l + r) / 2 + 1, r);
  seg[node] = min(seg[2 * node], seg[2 * node + 1]);
}

int trav(int node, int from, int bound) { // premier i >= from tq lst[i] < bound
  if (seg[node] >= bound or iFin[node] < from)
    return -1;

  if (iDeb[node] == iFin[node])
    return iDeb[node];

  int lft = trav(2 * node, from, bound);
  if (lft == -1)
    return trav(2 * node + 1, from, bound);
  return lft;
}

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

  int nbChambres = readInt();
  vector<int> type(nbChambres - 1);
  for (int &t : type)
    t = readInt() - 1;

  vector<vector<int>> posType(nbChambres);
  for (int i = 0; i < nbChambres; ++i) {
    int cnt = readInt();
    while (cnt--) {
      int t = readInt() - 1;
      posType[t].push_back(i);
    }
  }
  lst.resize(nbChambres);
  for (int i = 1; i < nbChambres; ++i) {
    int t = type[i - 1];
    int fst = lower_bound(posType[t].begin(), posType[t].end(), i) -
              posType[t].begin();
    --fst;
    if (fst < 0)
      lst[i] = -1;
    else
      lst[i] = posType[t][fst];
  }
  build(1, 1, nbChambres - 1);
  vector<int> L(nbChambres), R(nbChambres);

  for (int iChambre = 0; iChambre < nbChambres; ++iChambre) {
    L[iChambre] = R[iChambre] = iChambre;
    while (L[iChambre] >= 0) {
      if (R[iChambre] + 1 < nbChambres) {
        int q = trav(1, R[iChambre] + 1, L[iChambre]);
        if (q == -1)
          R[iChambre] = nbChambres - 1;
        else
          R[iChambre] = q - 1;
      }
      if (L[iChambre] == 0)
        break;

      // can we reduce L[iChambre] ?
      int t = type[L[iChambre] - 1];
      auto fst =
          lower_bound(posType[t].begin(), posType[t].end(), L[iChambre]) -
          posType[t].begin();
      if (fst == (int)posType[t].size() or posType[t][fst] > R[iChambre])
        break;
      L[iChambre] = L[L[iChambre] - 1];
      R[iChambre] = max(R[iChambre], R[L[iChambre]]);
    }
  }

  int Q = readInt();
  while (Q--) {
    int from = readInt() - 1, to = readInt() - 1;
    cout << (L[from] <= to and to <= R[from] ? "YES" : "NO") << '\n';
  }
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 15 / 15
• Subtask 4: 75 / 75