Submission #1224930

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224930		AmirAli_H1	Split the Attractions (IOI19_split)	C++17	100 / 100	96 ms	30908 KiB

split

// In the name of Allah

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

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = (1 << 18) + 4;

int n, m;
int Ax, Bx, Cx; vector<int> Rx = {1, 2, 3};
vector<int> adjx[maxn], adj[maxn];
vector<pii> E; vector<int> res;
int mark[maxn], p[maxn], sz[maxn], R;

int get(int a) {
	return (p[a] == a) ? a : p[a] = get(p[a]);
}

void merge(int a, int b) {
	a = get(a); b = get(b);
	if (a == b) return ;
	if (sz[a] > sz[b]) swap(a, b);
	p[a] = b; sz[b] += sz[a];
}

void fix_abc() {
	if (Cx < Bx) {
		swap(Bx, Cx); swap(Rx[1], Rx[2]);
	}
	if (Cx < Ax) {
		swap(Ax, Cx); swap(Rx[0], Rx[2]);
	}
	if (Bx < Ax) {
		swap(Ax, Bx); swap(Rx[0], Rx[1]);
	}
}

void dfsx(int v) {
	mark[v] = 1;
	for (int u : adjx[v]) {
		if (!mark[u]) {
			adj[u].pb(v); adj[v].pb(u);
			dfsx(u);
		}
	}
}

void pre_dfs(int v, int p = -1) {
	sz[v] = 1;
	for (int u : adj[v]) {
		if (u == p) continue;
		pre_dfs(u, v);
		sz[v] += sz[u];
	}
}

int get_cent(int v, int p, int SZ) {
	for (int u : adj[v]) {
		if (u == p) continue;
		if (sz[u] * 2 > SZ) return get_cent(u, v, SZ);
	}
	return v;
}

void res_dfs(int v, int fx) {
	if (R <= 0) return ;
	mark[v] = 1; res[v] = fx; R--;
	for (int u : adj[v]) {
		if (!mark[u]) res_dfs(u, fx);
	}
}

void col_dfs(int v, int p) {
	for (int u : adj[v]) {
		if (u == p) continue;
		merge(v, u);
		col_dfs(u, v);
	}
}

void calx(int v, int u) {
	fill(mark, mark + n, 0);
	fill(all(res), Rx[2]);
	mark[v] = 1; R = Ax; res_dfs(u, Rx[0]);
	mark[v] = 0; R = Bx; res_dfs(v, Rx[1]);
	return ;
}

void get_res(int v) {
	for (int u : adj[v]) {
		if (sz[get(u)] >= Ax) {
			calx(v, u);
			return ;
		}
	}
}

vector<int> find_split(int nx, int ax, int bx, int cx, vector<int> px, vector<int> qx) {
	n = nx; m = len(px); res.resize(n);
	Ax = ax; Bx = bx; Cx = cx; fix_abc();
	for (int i = 0; i < m; i++) {
		int u = px[i], v = qx[i];
		adjx[u].pb(v); adjx[v].pb(u);
		E.pb(Mp(u, v));
	}
	dfsx(0);
	pre_dfs(0); int v = get_cent(0, -1, sz[0]);
	iota(p, p + n, 0); fill(sz, sz + n, 1);
	for (int u : adj[v]) col_dfs(u, v);
	for (int u : adj[v]) {
		if (sz[get(u)] >= Ax) {
			calx(v, u);
			return res;
		}
	}
	for (auto f : E) {
		int ux = f.F, vx = f.S;
		if (ux == v || vx == v || get(ux) == get(vx)) continue;
		merge(ux, vx);
		adj[ux].pb(vx); adj[vx].pb(ux);
		if (sz[get(ux)] >= Ax) {
			get_res(v);
			return res;
		}
	}
	return res;
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 24 / 24
• Subtask 5: 36 / 36