Submission #672813

#	Time	Username	Problem	Language	Result	Execution time	Memory
672813		ghostwriter	Regions (IOI09_regions)	C++17	35 / 100	2993 ms	40500 KiB

regions

// #pragma GCC optimize ("Ofast")
// #pragma GCC target ("avx2")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
    #include <debug.h>
#else
    #define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
// #define int long long
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
#define FOR(i, l, r) for (int i = (l); i <= (r); ++i)
#define FOS(i, r, l) for (int i = (r); i >= (l); --i)
#define FRN(i, n) for (int i = 0; i < (n); ++i)
#define FSN(i, n) for (int i = (n) - 1; i >= 0; --i)
#define EACH(i, x) for (auto &i : (x))
#define WHILE while
template<typename T> T gcd(T a, T b) { T d2 = (a | b) & -(a | b); a /= d2; b /= d2; WHILE(b) { a = a % b; swap(a, b); } return a * d2; }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
void _assert(bool statement) { if (statement) return; cerr << "\n>> Assertion failed!\n"; exit(0); }
void _assert(bool statement, const str &message) { if (statement) return; cerr << "\n>> Assertion failed: " << message << '\n'; exit(0); }
void _error(const str &message) { cerr << "\n>> Error: " << message << '\n'; exit(0); }
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Tran The Bao - ghostwriter
    Training for VOI23 gold medal
----------------------------------------------------------------
    GOAT
----------------------------------------------------------------
*/
const int N = 2e5 + 5;
const int D = 455;
int n, r, q, h[N], pos[N], tin[N], s[N], f[D][N], f1[D][N], pre[N], num = 0, timer = 0;
vi adj[N], region[N], region1[N];
void input(int test_id) {
	cin >> n >> r >> q;
	cin >> h[1];
	FOR(i, 2, n) {
		int s;
		cin >> s >> h[i];
		adj[s].pb(i);
	}
}
void dfs(int u) {
	tin[u] = ++timer;
	s[u] = 1;
	EACH(v, adj[u]) {
		dfs(v);
		s[u] += s[v];
	}
}
void dfs1(int u, int cnt) {
	cnt += (pos[h[u]] == num? 1 : 0);
	f[num][h[u]] += cnt;
	EACH(v, adj[u]) dfs1(v, cnt);
}
void dfs2(int u, int &cnt) {
	int cnt1 = 1;
	EACH(v, adj[u]) dfs2(v, cnt1);
	f1[num][h[u]] += cnt1;
	cnt += cnt1;
}
int cal(int r1, int r2) {
	if (region[r1].empty() || region[r2].empty()) return 0;
	if (sz(region[r1]) > D) return f[pos[r1]][r2];
	if (sz(region[r2]) > D) return f1[pos[r2]][r1];
	vi &a = region[r1], &a1 = region1[r1], &b = region[r2];
	int pos = 0, rs = 0;
	EACH(i, a) {
		WHILE(pos < sz(b) && tin[b[pos]] < tin[i]) ++pos;
		pre[i] = pos;
	}
	pos = 0;
	EACH(i, a1) {
		WHILE(pos < sz(b) && tin[b[pos]] <= tin[i] + s[i] - 1) ++pos;
		--pos;
		if (pre[i] <= pos) rs += pos - pre[i] + 1;
	}
	return rs;
}
void solve(int test_id) {
	dfs(1);
	FOR(i, 1, n) region[h[i]].pb(i);
	FOR(i, 1, r) {
		if (region[i].empty()) continue;
		auto cmp = [&](const int &a, const int &b) -> bool { return tin[a] < tin[b]; };
		auto cmp1 = [&](const int &a, const int &b) -> bool { return tin[a] + s[a] < tin[b] + s[b]; };
		region1[i] = region[i];
		sort(all(region[i]), cmp);
		sort(all(region1[i]), cmp1);
	}
	FOR(i, 1, r) {
		if (sz(region[i]) <= D) continue;
		pos[i] = ++num;
		dfs1(1, 0);
		int ss = 0;
		dfs2(1, ss);
	}
	WHILE(q--) {
		int r1, r2;
		cin >> r1 >> r2;
		cout << cal(r1, r2) << endl;
	}
}
void reinit(int test_id) {

}
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);
    int test_num = 1;
    // cin >> test_num; // comment if the problem does not requires multitest
    FOR(i, 1, test_num) {
        input(i); // input in noninteractive problems for case #i
        solve(i); // main function to solve case #i
        reinit(i); // reinit global data to default used in case #i
    }
    #ifdef LOCAL
        cerr << "\nTime: " << setprecision(5) << fixed << (ldb)clock() / CLOCKS_PER_SEC << "ms.\n";
    #endif
    return 0;
}
/*
----------------------------------------------------------------
From Benq:
    stuff you should look for
        * int overflow, array bounds
        * special cases (n=1?)
        * do smth instead of nothing and stay organized
        * WRITE STUFF DOWN
        * DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/

• Subtask 1: 15 / 15
• Subtask 2: 20 / 85