Submission #804426

#	Time	Username	Problem	Language	Result	Execution time	Memory
804426		marvinthang	Through Another Maze Darkly (CCO21_day1problem3)	C++17	25 / 25	1193 ms	267264 KiB

Main

/*************************************
*    author: marvinthang             *
*    created: 03.08.2023 15:10:06    *
*************************************/

#include <bits/stdc++.h>

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i-- > 0; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }

// index from 0
template <class T = int>
    struct Fenwick {

        T *bit = nullptr;
        int n;

        Fenwick(int _n = 0) {
            resize(_n);
        }

        void reset(void) {
            fill(bit, bit + 1 + n, T(0));
        }

        void resize(int _n) {
            if (bit != nullptr) delete[] bit;
            n = _n;
            bit = new T[n + 1];
            reset();
        }

        void update(int i, T val) {
            assert(0 <= i);
            ++i;
            for (; i <= n; i += i & -i) bit[i] += val;
        }

        T get(int i) {
            if (i < 0) return T(0);
            ++i;
            i = min(i, n);
            T res(0);
            for (; i > 0; i -= i & -i)
                res += bit[i];
            return res;
        }

        int upper_bound(T val) {
            int res = 0;
            for (int i = __lg(n); i >= 0; --i) {
                if ((res | MASK(i)) <= n && val >= bit[res | MASK(i)]) {
                    res |= MASK(i);
                    val -= bit[res];
                }
            }
            return res;
        }

        int lower_bound(T val) {
            int res = 0;
            for (int i = __lg(n); i >= 0; --i) {
                if ((res | MASK(i)) <= n && val > bit[res | MASK(i)]) {
                    res |= MASK(i);
                    val -= bit[res];
                }
            }
            return res;
        }

    };

// end of template

const int MAX = 8e5 + 5;

int N, Q;
vector <int> adj[MAX];

void init(void) {
	cin >> N >> Q;
	FORE(i, 1, N) {
		int d; cin >> d;
		adj[i].resize(d);
		cin >> adj[i];
		rotate(adj[i].begin(), adj[i].begin() + 1, adj[i].end());
	}
}

int start[MAX];
vector <int> events[MAX];
vector <int> tour;

void dfs(int u, int pos) {
	rotate(adj[u].begin(), adj[u].begin() + pos, adj[u].end());
	if (u != 1) {
		events[start[u]].push_back(tour.size());
		tour.push_back(u);
	}
	REP(i, adj[u].size()) {
		int v = adj[u][i];
		start[v] = start[u] + (i < (int) adj[u].size() - pos);
		int p = find(ALL(adj[v]), u) - adj[v].begin();
		adj[v].erase(adj[v].begin() + p);
		dfs(v, p);
		events[start[v]].push_back(tour.size());
		tour.push_back(u);
	}
}

long long pref[MAX];
int res[MAX];
vector <pair <long long, int>> queriesAt[MAX];

void process(void) {
	dfs(1, adj[1].size());
	int sum = 0;
	REP(i, N) {
		sum += events[i].size();
		pref[i + 1] = pref[i] + sum;
	}
	REP(i, Q) {
		long long k; cin >> k;
		if (k > pref[N]) res[i] = tour[(k - pref[N] - 1) % tour.size()];
		else {
			int p = lower_bound(pref, pref + N + 1, k) - pref - 1;
			queriesAt[p].emplace_back(k - pref[p], i);
		}
	}
	Fenwick <int> bit(tour.size());
	REP(i, N) {
		for (int x: events[i]) bit.update(x, +1);
		for (auto [k, id]: queriesAt[i]) res[id] = tour[bit.lower_bound(k)];
	}
	REP(i, Q) cout << res[i] << '\n';
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
	file("E");
	init();
	process();
	cerr << "Time elapsed: " << TIME << " s.\n";
	return (0^0);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:30:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:172:2: note: in expansion of macro 'file'
  172 |  file("E");
      |  ^~~~
Main.cpp:30:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:172:2: note: in expansion of macro 'file'
  172 |  file("E");
      |  ^~~~

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 12 / 12
• Subtask 4: 5 / 5