Submission #603685

#	Time	Username	Problem	Language	Result	Execution time	Memory
603685		SeDunion	Split the Attractions (IOI19_split)	C++17	100 / 100	116 ms	31216 KiB

split

#include "split.h"
#include<algorithm>
#include<iostream>
#include<vector>
#include<assert.h>

using namespace std;
const int N = 2e5 + 123;

vector<int>g[N], tg[N];

int used[N];

int n, a, b, c;

vector<int>ans;

int V = -1;

int tin[N], tout[N], timer, sz[N], fup[N], par[N];

void dfs(int v) {
	used[v] = 1;
	sz[v] = 1;
	tin[v] = fup[v] = timer++;
	for (int to : g[v]) {
		if (!used[to]) {
			tg[v].emplace_back(to);
			par[to] = v;
			dfs(to);
			sz[v] += sz[to];
			fup[v] = min(fup[v], fup[to]);
		} else {
			fup[v] = min(fup[v], tin[to]);
		}
	}
	if (sz[v] >= a && V == -1) V = v;
	tout[v] = timer++;
}

bool cmp(int a, int b) {
	return tin[a] < tin[b];
}

bool upper(int a, int b) { return tin[a] <= tin[b] && tout[a] >= tout[b]; } 

int gg[4];

void tree(int v, int c, int &d) {
	if (!d || ans[v] != 3) return;
	--d;
	ans[v] = c;
	for (int to : tg[v]) tree(to, c, d);
}

void eert(int v, int c, int &d) {
	if (!d || ans[v] != 3) return;
	--d;
	ans[v] = c;
	for (int to : g[v]) eert(to, c, d);
}

vector<int> find_split(int n_, int a_, int b_, int c_, vector<int> p, vector<int> q) {
	n = n_, a = a_, b = b_, c = c_;
	if (a > b) swap(a, b);
	if (b > c) swap(b, c);
	if (a > b) swap(a, b);
	if (a_ == a && b_ == b && c_ == c) gg[1] = 1, gg[2] = 2, gg[3] = 3;
	if (a_ == a && b_ == c && c_ == b) gg[1] = 1, gg[3] = 2, gg[2] = 3;
	if (a_ == b && b_ == a && c_ == c) gg[2] = 1, gg[1] = 2, gg[3] = 3;
	if (a_ == b && b_ == c && c_ == a) gg[2] = 1, gg[3] = 2, gg[1] = 3;
	if (a_ == c && b_ == a && c_ == b) gg[3] = 1, gg[1] = 2, gg[2] = 3;
	if (a_ == c && b_ == b && c_ == a) gg[3] = 1, gg[2] = 2, gg[1] = 3;
	// a <= b <= c
	// a <= n/3 ?
	// b <= n/2 ?
	int m = p.size();
	for (int i = 0 ; i < m ; ++ i) {
		g[p[i]].emplace_back(q[i]);
		g[q[i]].emplace_back(p[i]);
	}
	ans = vector<int>(n, 3);
	par[0] = -1;
	dfs(0);
	if (V == -1) return vector<int>(n, 0);
	int v = V;
	if (sz[v] + b <= n) {
		tree(v, 1, a);
		eert(par[v], 2, b);
	} else {
		ans[v] = 2;
		b--;
		for (int to : tg[v]) if (fup[to] > tin[v]) tree(to, 2, b);
		for (int to : tg[v]) if (fup[to] <= tin[v]) tree(to, 2, b);
		if (par[V] != -1) eert(par[v], 1, a);
		if (a) return vector<int>(n, 0);
	}
	for (int &i : ans) i = gg[i];
	return ans;
}

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