Submission #765764

#	Time	Username	Problem	Language	Result	Execution time	Memory
765764		marvinthang	Simurgh (IOI17_simurgh)	C++17	30 / 100	78 ms	2660 KiB

simurgh

/*************************************
*    author: marvinthang             *
*    created: 25.06.2023 11:26:35    *
*************************************/

#include "simurgh.h"
#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--; )
#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 << '}'; }

struct DisjointSet {
    
    int n, *lab = nullptr;

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

    void reset(void) {
        memset(lab, -1, (n + 1) * sizeof(int));
    }

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

    int find(int u) {
        assert(u <= n);
        return lab[u] < 0 ? u : lab[u] = find(lab[u]);
    }

    bool connected(int u, int v) { return find(u) == find(v); }
    bool isRoot(int u) { return lab[u] < 0; }
    int size(int u) { return -lab[find(u)]; }

    bool join(int u, int v) {
        if ((u = find(u)) == (v = find(v))) return false;
        if (lab[u] > lab[v]) swap(u, v);
        lab[u] += lab[v];
        lab[v] = u;
        return true;
    }

};

using DSU = DisjointSet;

// end of template

vector <int> find_roads(int n, vector <int> u, vector <int> v) {
	int m = u.size();
	DSU dsu(n);
	vector <int> on_tree;
	vector <int> rem;
	REP(i, m) (dsu.join(u[i], v[i]) ? on_tree : rem).push_back(i);
	int cur = count_common_roads(on_tree);
	vector <int> res;
	// cout << on_tree << '\n';
	REP(i, n - 1) {
		dsu.reset();
		REP(j, n - 1) if (j != i) dsu.join(u[on_tree[j]], v[on_tree[j]]);
		int f = on_tree[i];
		vector <int> g;
		int in_i = 0;
		REPD(j, rem.size()) if (!dsu.connected(u[rem[j]], v[rem[j]])) {
			// cout << rem[j] << ' ' << u[rem[j]] << ' ' << v[rem[j]] << '\n';
			on_tree[i] = rem[j];
			int nxt = count_common_roads(on_tree);
			if (nxt > cur) {
				in_i = -1;
				res.push_back(rem[j]);
			} else if (nxt < cur) {
				if (!in_i) {
					res.push_back(f);
					in_i = 1;
				}
			} else g.push_back(rem[j]);
			// swap(rem[j], rem.back());
			// rem.pop_back();
		}
		if (in_i >= 0) res.insert(res.end(), ALL(g));
		if (!in_i) res.push_back(f);
		// cout << res << '\n';
		// cout << "-----------\n";
		on_tree[i] = f;
	}
	// cout << res << '\n';
	sort(ALL(res));
	res.erase(unique(ALL(res)), res.end());
	return res;
}

#ifdef LOCAL
#include "simurgh.h"

#include <cstdio>
#include <cassert>
#include <vector>
#include <cstdlib>
#include <string>

using namespace std;

static int MAXQ = 30000;

static int n, m, q = 0;
static vector<int> u, v;
static vector<bool> goal;

static void wrong_answer() {
	printf("NO\n");
	exit(0);
}

static bool is_valid(const vector<int>& r) {
	if(int(r.size()) != n - 1)
		return false;

	for(int i = 0; i < n - 1; i++)
		if (r[i] < 0 || r[i] >= m)
			return false;

	return true;
}

static int _count_common_roads_internal(const vector<int>& r) {
	if(!is_valid(r))
		wrong_answer();

	int common = 0;
	for(int i = 0; i < n - 1; i++) {
		bool is_common = goal[r[i]];
		if (is_common)
			common++;
	}

	return common;	
}

int count_common_roads(const vector<int>& r) {
	q++;
	if(q > MAXQ)
		wrong_answer();

	return _count_common_roads_internal(r);
}

int main() {
	file("simurgh");
	assert(2 == scanf("%d %d", &n, &m));

	u.resize(m);
	v.resize(m);

	for(int i = 0; i < m; i++)
		assert(2 == scanf("%d %d", &u[i], &v[i]));

	goal.resize(m, false);

	for(int i = 0; i < n - 1; i++) {
		int id;
		assert(1 == scanf("%d", &id));
		goal[id] = true;
	}

	vector<int> res = find_roads(n, u, v);

	if(_count_common_roads_internal(res) != n - 1)
		wrong_answer();

	printf("YES\n");

	return 0;
}
#endif

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30