Submission #912649

#	Time	Username	Problem	Language	Result	Execution time	Memory
912649		Wansur	Split the Attractions (IOI19_split)	C++14	40 / 100	93 ms	35664 KiB

split

#include <bits/stdc++.h>
#define f first
#define s second
#define ent '\n'

using namespace std;
typedef long long ll;
const int mx=2e5+12;

vector<pair<int,int>> del;
vector<pair<int,int>> add;
vector<int> ans;
pair<int,int> fup[mx];
vector<int> g[mx];
set<int> e[mx];
int Ans[mx];
int par[mx];
int tin[mx];
int ver[mx];
int sz[mx];
int pos[]={1,2,3};
int timer;

void calc(int v){
	sz[v]=1;
	for(int to:g[v]){
		if(sz[to]>0)continue;
		calc(to);
		par[to]=v;
		e[v].insert(to);
		sz[v]+=sz[to];
	}
}

void dfs(int v,int p){
	tin[v]=fup[v].f=++timer;
	fup[v].s=v;
	ver[tin[v]]=v;
	for(int to:g[v]){
		if(to==p)continue;
		if(tin[to]>0){
			fup[v]=min(fup[v],{tin[to],v});
		}
		else{
			dfs(to,v);
			fup[v]=min(fup[v],fup[to]);
		}
	}
}

void get(int v,int p,int &cnt,int t){
	if(!cnt)return;
	Ans[v]=pos[t];
	cnt--;
	if(!cnt)return;
	for(int to:e[v]){
		get(to,v,cnt,t);
	}
}

void get(int v,int n,int a,int b,int c){
	vector<int> edg;
	for(int to:e[v]){
		edg.push_back(to);
	}
	int s=sz[v];
	for(int to:edg){
		if(s-sz[to]<a){
			break;
		}
		if(fup[to].f<tin[v]){
			s-=sz[to];
			e[v].erase(to);
			add.push_back({v,to});
			e[ver[fup[to].f]].insert(fup[to].s);
			del.push_back({ver[fup[to].f],fup[to].s});
		}
	}
	e[par[v]].erase(v);
	add.push_back({par[v],v});
	if(s>=a && n-s>=b){
		get(v,0,a,0);
		get(0,0,b,1);
		for(int i=0;i<n;i++){
			ans[i]=Ans[i];
			if(!ans[i])ans[i]=pos[2];
		}
	}
	else if(s>=b && n-s>=a){
		get(v,0,b,1);
		get(0,0,a,0);
		for(int i=0;i<n;i++){
			ans[i]=Ans[i];
			if(!ans[i])ans[i]=pos[2];
		}
	}
}

std::vector<int> find_split(int n, int a, int b, int c, std::vector<int> p, std::vector<int> q){
	for(int i=0;i<p.size();i++){
		g[p[i]].push_back(q[i]);
		g[q[i]].push_back(p[i]);
	}
	if(a>b){
		swap(a,b);
		swap(pos[0],pos[1]);
	}
	if(a>c){
		swap(a,c);
		swap(pos[0],pos[2]);
	}
	if(b>c){
		swap(b,c);
		swap(pos[1],pos[2]);
	}
	calc(0);
	int v=-1;
	vector<int> d;
	for(int i=0;i<n;i++){
		ans.push_back(0);
	}
	for(int i=1;i<n;i++){
		if(sz[i]<a)continue;
		if(sz[i]>=a){
			d.push_back(i);
		}
	}
	sort(d.begin(),d.end(),[](int i,int j){
		return sz[i]<sz[j];
	});
	for(int v:d){
		del.clear();
		add.clear();
		get(v,n,a,b,c);
		if(ans[0]!=0)return ans;
		for(auto x:del){
			e[x.f].erase(x.s);
		}
		for(auto x:add){
			e[x.f].insert(x.s);
		}
	}
	return ans;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:100:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |  for(int i=0;i<p.size();i++){
      |              ~^~~~~~~~~
split.cpp:117:6: warning: unused variable 'v' [-Wunused-variable]
  117 |  int v=-1;
      |      ^

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36