Submission #71042

#	Time	Username	Problem	Language	Result	Execution time	Memory
71042		qkxwsm	Cats or Dogs (JOI18_catdog)	C++17	100 / 100	389 ms	86764 KiB

catdog

#include "catdog.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

struct chash
{
	int operator()(int x) const
	{
		x ^= (x >> 20) ^ (x >> 12);
		return x ^ (x >> 7) ^ (x >> 4);
	}
	int operator()(long long x) const
	{
		return x ^ (x >> 32);
	}
};

template<typename T> using orderedset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using hashtable = gp_hash_table<T, U, chash>;

template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
template<class T, class U>
T normalize(T x, U mod = 1000000007)
{
	return (((x % mod) + mod) % mod);
}
static long long randomizell(long long mod)
{
	return ((1ll << 45) * rand() + (1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}
static int randomize(int mod)
{
	return ((1ll << 15) * rand() + rand()) % mod;
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define debug(x) cerr << #x << " = " << x << endl;

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-10;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 100013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<pll, pll> ppp;
typedef pair<ld, ld> pdd;

int N;
vector<int> edge[MAXN];
int parent[MAXN], depth[MAXN];
int heavy[MAXN], head[MAXN], ranking[MAXN], subtree[MAXN], siz[MAXN];
int arr[MAXN];
pll dp[MAXN];
pll big[3] = {{0, 0}, {0, INF}, {INF, 0}};

ppp comb(ppp lt, ppp rt)
{
		ppp res;
		res.fi.fi = min(lt.fi.fi + rt.fi.fi, lt.fi.se + rt.se.fi);
		res.fi.se = min(lt.fi.fi + rt.fi.se, lt.fi.se + rt.se.se);
		res.se.fi = min(lt.se.fi + rt.fi.fi, lt.se.se + rt.se.fi);
		res.se.se = min(lt.se.fi + rt.fi.se, lt.se.se + rt.se.se);
		return res;
}
struct segtree
{
	//range[L...R] = cost to change from color x to color y at L...R INCLUDING ALL THE DPS ON THE WAY
	//excepts ranges are reversed: L...R means cost from R...L - 1
	vector<ppp> seg;
	void resize(int x)
	{
		seg.resize(x);
	}
	void update(int w, int L, int R, int a, pll p)
	{
		if (a < L || R < a)
		{
			return;
		}
		if (L == R)
		{
			//each time you change something, make it super expensive to update its parents
			seg[w].fi.fi += p.fi;
			seg[w].fi.se += p.fi;
			seg[w].se.fi += p.se;
			seg[w].se.se += p.se;
			return;
		}
		int mid = (L + R) >> 1;
		update(w << 1, L, mid, a, p);
		update(w << 1 | 1, mid + 1, R, a, p);
		seg[w] = comb(seg[w << 1], seg[w << 1 | 1]);
	}
};

//cost of considering x -> x + 1

segtree seg[MAXN];

pll operator + (const pll &a, const pll &b)
{
	return {a.fi + b.fi, a.se + b.se};
}
pll operator - (const pll &a, const pll &b)
{
	return {a.fi - b.fi, a.se - b.se};
}
pll trans(int u, int v)
{
	return big[v] - big[u];
}
void dfs(int u)
{
	subtree[u] = 1;
	for (int v : edge[u])
	{
		if (v == parent[u]) continue;
		parent[v] = u;
		depth[v] = depth[u] + 1;
		dfs(v);
		subtree[u] += subtree[v];
	}
	heavy[u] = N;
	for (int v : edge[u])
	{
		if (v == parent[u]) continue;
		if (subtree[v] * 2 >= subtree[u]) heavy[u] = v;
	}
}
void dfs_heavy(int u)
{
	if (heavy[u] != N)
	{
		head[heavy[u]] = head[u];
		ranking[heavy[u]] = ranking[u] + 1;
		dfs_heavy(heavy[u]);
	}
	for (int v : edge[u])
	{
		if (v == parent[u]) continue;
		if (v == heavy[u]) continue;
		ranking[v] = 0;
		head[v] = v;
		dfs_heavy(v);
	}
	return;
}
void initialize(int n, vector<int> a, vector<int> b)
{
	N = n;
	for (int i = 0; i < N - 1; i++)
	{
		int u = a[i], v = b[i];
		u--; v--;
		edge[u].PB(v);
		edge[v].PB(u);
	}
	parent[N] = N; parent[0] = N;
	dfs(0);
	dfs_heavy(0);
	for (int i = 0; i < N; i++)
	{
		// cerr << head[i] << ' ';
		siz[head[i]]++;
	}
	// cerr << endl;
	for (int i = 0; i < N; i++)
	{
		ranking[i] = siz[head[i]] - ranking[i] - 1;
	}
	for (int i = 0; i < N; i++)
	{
		if (siz[i] == 0) continue;
		seg[i].resize((1 << (33 - __builtin_clz(siz[i] + 1))) + 1);
		fill(seg[i].seg.begin(), seg[i].seg.end(), MP(MP(0, 1), MP(1, 0)));
	}
}
//0, 3, 4; 1, 2; 5, 6; 8, 9
//0 -> 3 -> 4; 2 -> 1; 6 -> 5; 8; 9;
void upd(int u, pll p)
{
	//cost here is actually cost L...R + 1; we want to change cost L, L + 1 once L gets changed
	//each seg INCLUDES the guys from its bad children!!!
	// cerr << "upd " << u << ' ' << p.fi << ' ' << p.se << endl;
	ppp stor = seg[head[u]].seg[1];
	pll was = {min(stor.fi.fi, stor.se.fi), min(stor.fi.se, stor.se.se)};
	seg[head[u]].update(1, 0, siz[head[u]] - 1, ranking[u], p);
	stor = seg[head[u]].seg[1];
	pll cur = {min(stor.fi.fi, stor.se.fi), min(stor.fi.se, stor.se.se)};
	// cerr << "ending at " << parent[head[u]] << " increases " << (cur - was).fi << ' ' << (cur - was).se << endl;
	// cerr << cur1.fi << ' ' << cur1.se << endl;
	if (head[u] == 0)
	{
		return;
	}
	upd(parent[head[u]], cur - was);
}
int setval(int u, int v)
{
	// cerr << "setval " << u << ' ' << v << endl;
	pll change = trans(arr[u], v);
	arr[u] = v;
	upd(u, change);
	ppp ans = seg[0].seg[1];
	// cerr << "color " << v << " ans " << ans.fi.fi << ' ' << ans.fi.se << ' ' << ans.se.fi << ' ' << ans.se.se << endl;
	return min(min(ans.fi.fi, ans.fi.se), min(ans.se.fi, ans.se.se));
}
int cat(int u)
{
	u--;
	return setval(u, 1);
}
int dog(int u)
{
	u--;
	return setval(u, 2);
}
int neighbor(int u)
{
	u--;
	return setval(u, 0);
}

Compilation message (stderr)

catdog.cpp:44:12: warning: 'int randomize(int)' defined but not used [-Wunused-function]
 static int randomize(int mod)
            ^~~~~~~~~
catdog.cpp:40:18: warning: 'long long int randomizell(long long int)' defined but not used [-Wunused-function]
 static long long randomizell(long long mod)
                  ^~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 30 / 30
• Subtask 3: 62 / 62