Submission #397832

#	Time	Username	Problem	Language	Result	Execution time	Memory
397832		sinamhdv	Regions (IOI09_regions)	C++11	100 / 100	4352 ms	87460 KiB

regions

// IOI09_regions
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;

#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second

#define MAXN 200100
#define SQRT 120
#define BLK (MAXN / SQRT + 10)

int n, rc, q;
int a[MAXN];
vector<int> col[MAXN];
int par[MAXN];
int precnt[BLK][MAXN];
vector<int> cld[MAXN];
vector<int> big;
int sttime[MAXN], fntime[MAXN], timer;
int cnt[MAXN];
int colcnt[MAXN];

void dfs(int v)
{
	FOR(i, 0, (int)big.size()) if (big[i] != a[v]) precnt[i][a[v]] += cnt[big[i]];
	col[a[v]].pb(v);
	sttime[v] = timer++;
	for (int u : cld[v])
	{
		cnt[a[v]]++;
		dfs(u);
		cnt[a[v]]--;
	}
	fntime[v] = timer;
}

bool cmp(int x, int y)
{
	return sttime[x] < sttime[y];
}

int32_t main(void)
{
	fast_io;
	cin >> n >> rc >> q;
	cin >> a[1];
	colcnt[a[1]]++;
	FOR(i, 2, n + 1)
	{
		cin >> par[i] >> a[i];
		colcnt[a[i]]++;
		cld[par[i]].pb(i);
	}

	FOR(i, 1, rc + 1)
		if (colcnt[i] > SQRT)
			big.pb(i);

	dfs(1);
	
	dbgr(big.begin(), big.end());
	dbgr(sttime + 1, sttime + n + 1);
	dbgr(fntime + 1, fntime + n + 1);
	
	while (q--)
	{
		int x, y;
		cin >> x >> y;
		if (colcnt[x] > SQRT)
		{
			x = lower_bound(all(big), x) - big.begin();
			cout << precnt[x][y] << endl;
			continue;
		}
		int ans = 0;
		for (int u : col[x])
		{
			sttime[MAXN - 1] = fntime[u] - 1;
			ans += upper_bound(all(col[y]), MAXN - 1, cmp) - lower_bound(all(col[y]), u, cmp);
		}
		cout << ans << endl;
	}

	return 0;
}

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