Submission #51941

#	Time	Username	Problem	Language	Result	Execution time	Memory
51941		mareksom	File Paths (BOI15_fil)	C++17	33 / 100	268 ms	20832 KiB

fil

#ifndef LOCAL
#pragma GCC optimize ("O3")
#endif

#include <bits/stdc++.h>

using namespace std;

#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return {i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (c it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(x...) " [" #x ": " << (x) << "] "

using ld = long double;
using ll = long long;

constexpr int mod = 1000 * 1000 * 1000 + 7;
constexpr int odw2 = (mod + 1) / 2;

void OdejmijOd(int& a, int b) { a -= b; if (a < 0) a += mod; }
int Odejmij(int a, int b) { OdejmijOd(a, b); return a; }
void DodajDo(int& a, int b) { a += b; if (a >= mod) a -= mod; }
int Dodaj(int a, int b) { DodajDo(a, b); return a; }
int Mnoz(int a, int b) { return (ll) a * b % mod; }
void MnozDo(int& a, int b) { a = Mnoz(a, b); }
int Pot(int a, int b) { int res = 1; while (b) { if (b % 2 == 1) MnozDo(res, a); a = Mnoz(a, a); b /= 2; } return res; }
int Odw(int a) { return Pot(a, mod - 2); }
void PodzielDo(int& a, int b) { MnozDo(a, Odw(b)); }
int Podziel(int a, int b) { return Mnoz(a, Odw(b)); }
int Moduluj(ll x) { x %= mod; if (x < 0) x += mod; return x; }

template <typename T> T Maxi(T& a, T b) { return a = max(a, b); }
template <typename T> T Mini(T& a, T b) { return a = min(a, b); }

constexpr int nax = 3005;

int n, m, k, s;
int ojc[nax];
int skok[nax];
int gleb[nax];
vector<int> cykle[nax];
vector<int> glebokosci;

bool Ok(int w, int len) {
  if (gleb[w] + len == k) {
    return true;
  }
  /*
  if (n <= 500 and m <= 500) {
    const int cpw = w;
    len += gleb[w];
    const int reszta = k - len;
    assert(reszta > 0);
    while (true) {
      for (int c : cykle[w]) {
        if (reszta % c == 0) {
          return true;
        }
      }
      if (w == 0) break;
      w = ojc[w];
    }
    w = cpw;
  }
  */
  while (true) {
    if (binary_search(glebokosci.begin(), glebokosci.end(), k - len - s)) {
      return true;
    }
    if (w == 0) break;
    len += skok[w];
    w = ojc[w];
  }
  return false;
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m >> k >> s;
  k--; s++;
  glebokosci.push_back(0);
  cykle[0].push_back(s);
  for (int i = 1; i <= n; i++) {
    cin >> ojc[i] >> skok[i];
    skok[i]++;
    gleb[i] = skok[i] + gleb[ojc[i]];
    glebokosci.push_back(gleb[i]);
    int j = i;
    int dlugosc = s;
    while (true) {
      cykle[j].push_back(dlugosc);
      if (j == 0) break;
      dlugosc += skok[j];
      j = ojc[j];
    }
  }
  sort(glebokosci.begin(), glebokosci.end());
  glebokosci.resize(unique(glebokosci.begin(), glebokosci.end()) - glebokosci.begin());
  for (int i = 0; i <= n; i++) {
    sort(cykle[i].begin(), cykle[i].end());
    cykle[i].resize(unique(cykle[i].begin(), cykle[i].end()) - cykle[i].begin());
  }

  while (m--) {
    int w, len;
    cin >> w >> len;
    if (Ok(w, len)) {
      cout << "YES\n";
    } else {
      cout << "NO\n";
    }
  }
  return 0;
}

• Subtask 1: 0 / 33
• Subtask 2: 33 / 33
• Subtask 3: 0 / 34