Submission #893488

#	Time	Username	Problem	Language	Result	Execution time	Memory
893488		Jawad_Akbar_JJ	Split the Attractions (IOI19_split)	C++17	100 / 100	126 ms	53744 KiB

split

#include <iostream>
#include <vector>
#include <set>
#include <cstring>
#include <cassert>
#include "split.h"
#include <algorithm>
 
using namespace std;
const int N = 1e5 + 10;

vector<vector<int>> v;
vector<int> nei[N],ch[N];
int A,B;
int mn[N];
int sz[N];
int hei[N];
bool seen[N];
int color[N];
bool found = false;
int K;
 
void dfs_color1(int u,int c){
	if (seen[u])
		return;
	if (K<=0)
		return;
	color[u] = c;
	seen[u] = true;
	K--;
	for (int i : nei[u]){
		if (seen[i])
			continue;
		dfs_color1(i,c);
	}
}

void dfs_color2(int u,int c){
	if (seen[u])
		return;
	if (K<=0)
		return;
	color[u] = c;
	seen[u] = true;
	K--;
	for (int i : ch[u]){
		if (seen[i])
			continue;
		dfs_color2(i,c);
	}
}

void dfs(int u,int h = 1){
	sz[u] = 1;
	hei[u] = h++;
	seen[u] = true;
	mn[u] = hei[u];
	for (int i : nei[u]){
		if (seen[i]){
			mn[u] = min(mn[u],hei[i]);
			continue;
		}
		ch[u].push_back(i);
		dfs(i,h);
		sz[u] += sz[i];
		mn[u] = min(mn[u],mn[i]);
	}
}
 
// #################################### reset seen
bool called = false;
void call(int u,set<int> s,int c,int Sz){
	if (called)
		return;
	called = true;
	memset(seen,false,sizeof seen);
	seen[u] = true;
	color[u] = c;
	Sz--;
	K = Sz;
	for (int i : s)
		dfs_color2(i,c);
}
 
void dfs2(int u){
	int p1 = sz[u];
	int p2 = sz[1] - sz[u];
 
	set<int> s;
 
	for (int  i : ch[u]){
		s.insert(i);
		dfs2(i);
		if (found)
          	return;
	}
 
	if (p1>=A and p2>=B){
		call(u,s,v[0][1],A);
		K = B;
		dfs_color1(1,v[1][1]);
		found = true;
		return;
	}
	else if (p1>=B and p2>=A){
		call(u,s,v[1][1],B);
		K = A;
		dfs_color1(1,v[0][1]);
		found = true;
		return;
	}
 
	for (int i : ch[u]){
		if (found)
			return;
		
		if (p1 - sz[i] >= A and mn[i] < hei[u]){
			s.erase(i);
			p1 -= sz[i];
			p2 += sz[i];
		}
		if (p1>=A and p2>=B){
			call(u,s,v[0][1],A);
			K = B;
			dfs_color1(1,v[1][1]);
			found = true;
			return;
		}
		if (p1>=B and p2>=A){
			call(u,s,v[1][1],B);
			K = A;
			dfs_color1(1,v[0][1]);
			found = true;
			return;
		}
	}
}
 
vector<int> find_split(int n,int a,int b,int c,vector<int> p,vector<int> q){
	int m = p.size();
 
	for (int i=0;i<m;i++){
		p[i]++;
		q[i]++;
		nei[p[i]].push_back(q[i]);
		nei[q[i]].push_back(p[i]);
	}
	v.push_back({a,1});
	v.push_back({b,2});
	v.push_back({c,3});
 
	sort(begin(v),end(v));
 
	A = v[0][0];
	B = v[1][0];
 
	dfs(1,1);
 
	memset(seen,false,sizeof seen);
 
	dfs2(1);

	vector<int> col;
	if (!found){
		for (int i=1;i<=n;i++)
			col.push_back(0);
		return col;
	}
	for (int i=1;i<=n;i++){
		if (color[i]==0)
			col.push_back(v[2][1]);
		else
			col.push_back(color[i]);
	}
	return col;
}

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