Submission #736218

#	Time	Username	Problem	Language	Result	Execution time	Memory
736218		marvinthang	Regions (IOI09_regions)	C++17	100 / 100	2216 ms	40956 KiB

regions

/*************************************
*    author: marvinthang             *
*    created: 05.05.2023 16:50:15    *
*************************************/

#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 << '}'; }

// end of template

const int MAX = 2e5 + 5;
const int MAX_R = 25e3 + 3;
const int BLOCK_SIZE = 500;

int N, R, Q, H[MAX];
vector <int> adj[MAX], List[MAX_R];
vector <pair <int, int>> List_f[MAX_R];
int id[MAX_R], res1[MAX / BLOCK_SIZE + 5][MAX_R], cnt[MAX_R], res2[MAX / BLOCK_SIZE + 5][MAX_R], numBig;
int tin[MAX], tout[MAX], treeSize[MAX];

void init(void) {
	cin >> N >> R >> Q;
	FORE(i, 1, N) {
		if (i > 1) {
			int p; cin >> p;
			adj[p].push_back(i);
		}
		cin >> H[i];
		++cnt[H[i]];
	}
}

void update(int u, int add) {
	if (~id[H[u]]) cnt[id[H[u]]] += add;
	for (int v: adj[u]) update(v, add);
}

void dfs(int u) {
	static int timeDfs = 0;
	tin[u] = ++timeDfs;
	if (~id[H[u]]) ++cnt[id[H[u]]];
	List_f[H[u]].emplace_back(tin[u] - 1, -1);
	List[H[u]].push_back(tin[u]);
	REP(i, numBig) res1[i][H[u]] += cnt[i];
	treeSize[u] = 1;
	for (int v: adj[u]) {
		dfs(v);
		treeSize[u] += treeSize[v];
	}
	if (~id[H[u]]) --cnt[id[H[u]]];
	tout[u] = timeDfs;
	List_f[H[u]].emplace_back(tout[u], 1);
}

void dfs2(int u) {
	int heavy = -1;
	for (int v: adj[u]) if (heavy == -1 || treeSize[heavy] < treeSize[v]) heavy = v;
	for (int v: adj[u]) if (v != heavy) {
		dfs2(v);
		update(v, -1);
	}
	if (heavy != -1) dfs2(heavy);
	for (int v: adj[u]) if (v != heavy) update(v, 1);
	if (~id[H[u]]) ++cnt[id[H[u]]];
	REP(i, numBig) res2[i][H[u]] += cnt[i];
}

void process(void) {
	memset(id, -1, sizeof(id));
	FORE(i, 1, R) {
		if (cnt[i] > BLOCK_SIZE) id[i] = numBig++;
		cnt[i] = 0;
	}
	dfs(1);
	dfs2(1);
	while (Q--) {
		int a, b; cin >> a >> b;
		if (~id[a]) cout << res1[id[a]][b] << endl;
		else if (~id[b]) cout << res2[id[b]][a] << endl;
		else {
			int res = 0, i = 0;
			for (auto [u, f]: List_f[a]) {
				while (i < (int) List[b].size() && List[b][i] <= u) ++i;
				res += f * i;
			}
			cout << res << endl;
		}
	}
}

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

Compilation message (stderr)

regions.cpp: In function 'int main()':
regions.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); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:127:2: note: in expansion of macro 'file'
  127 |  file("regions");
      |  ^~~~
regions.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); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:127:2: note: in expansion of macro 'file'
  127 |  file("regions");
      |  ^~~~

• Subtask 1: 15 / 15
• Subtask 2: 85 / 85