Submission #827090

#	Time	Username	Problem	Language	Result	Execution time	Memory
827090		vjudge1	Split the Attractions (IOI19_split)	C++17	40 / 100	92 ms	36232 KiB

split

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

//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")

//typedef long double ld;
typedef long long ll;
using namespace std;
 
struct node{double x,y;};
//double len(node a,node b)
//{return sqrt((a.x-b.x)*(a.x-b.y)+(a.y-b.y)*(a.x-b.y));}

struct seg{
	int m1,m2,sum,cnt;
};

const string out[2]={"No\n","Yes\n"};
const ll dx[]={0,0,1,-1,-1,1,1,-1};  
const ll dy[]={1,-1,0,0,-1,1,-1,1};
const int md=998244353;
const int mod=1e9+7;
const int mx=1e6+1; 
const int tst=1e5;
const bool T=0;

vector<pair<int,int>> orz;
vector<int> g[mx];
vector<int> ord;
bool used[mx];
int tin[mx];
int fup[mx];
int ans[mx];
int sz[mx];
int n,m,k;
int A,B,C;
int timer;
int cnt;
int ver;
bool ok;

void dfs(int v){
	used[v]=1;
	cnt++;
	if(cnt<=A){
		ans[v]=1;
	}
	else if(cnt<=A+B){
		ans[v]=2;
	}
	else{
		ans[v]=3;
	}
	for(int to:g[v]){
		if(!used[to]){
			dfs(to);
		}
	}
}

void dfs(int v,int p){
	used[v]=sz[v]=1;
	tin[v]=fup[v]=++timer;
	int mn=1e9,c=0;
	for(int to:g[v]){
		if(!used[to]){
			dfs(to,v);
			fup[v]=min(fup[v],fup[to]);
			mn=min(mn,fup[to]);
			sz[v]+=sz[to];
			c++;
		}
		if(used[to] && to!=p){
			fup[v]=min(fup[v],tin[to]);
		}
	}
	if(mn>=tin[v] && p && mn!=1e9){
		ord.push_back(v);
	}
	if(!p && c>1){
		ord.push_back(v);
	}
}

void dfst(int v,int p=0){
	sz[v]=1;
	for(int to:g[v]){
		if(to!=p){
			dfst(to,v);
			sz[v]+=sz[to];
		}
	}
	if(sz[v]>=A && n-sz[v]>=B){
		ver=v;
		ok=0;
	}
	if(sz[v]>=B && n-sz[v]>=A){
		ver=v;
		ok=1;
	}
}

void ddd(int v){
	used[v]=1;
	for(int to:g[v]){
		if(!used[to]){
			ddd(to);
			orz.push_back({v,to});
		}
	}
}

void dfs2(int v,bool f){
	cnt++;
	used[v]=1;
	if(cnt<=A && !f){
		ans[v]=1;
	}
	if(cnt<=B && f){
		ans[v]=2;
	}
	random_shuffle(g[v].begin(),g[v].end());
	for(int to:g[v]){
		if(!used[to]){
			dfs2(to,f);
		}
	}
}

vector<int> find_split(int N, int a, int b, int c, vector<int> p, vector<int> q){
	n=N;
	srand(time(0));
	m=p.size();
	A=a,B=b,C=c;
	int mn=1e9,pos=0;
	bool okk=1;
	for(int i=0;i<p.size();i++){
		p[i]++;
		q[i]++;
		g[p[i]].push_back(q[i]);
		g[q[i]].push_back(p[i]);
	}
	for(int i=1;i<=n;i++){
		if(g[i].size()>2){
			okk=0;
		}
		mn=min(mn,(int)g[i].size());
		if(mn==(int)g[i].size()){
			pos=i;
		}
	}
	if(okk){
		dfs(1);
		vector<int> v;
		for(int i=1;i<=n;i++){
			v.push_back(ans[i]);
		}
		return v;
	}
	if(a==1){
		dfs(1,0);
		for(int i=1;i<=n;i++){
			used[i]=0;
		}
		for(int x:ord){
			used[x]=1;
		}
		int u=1;
		while(used[u]){
			u++;
		}
		vector<int> v;
		ans[u]=1;
		for(int i=1;i<=n;i++){
			used[i]=0;
		}
		used[u]=1;
		cnt=1;
		if(u!=1)dfs(1);
		else dfs(2);
		for(int i=1;i<=n;i++){
			v.push_back(ans[i]);
		}
		return v;
	}
	ddd(1);
	for(int i=1;i<=n;i++){
		g[i].clear();
	}
	for(auto x:orz){
		g[x.f].push_back(x.s);
		g[x.s].push_back(x.f);
	}
	for(int i=1;i<=n;i++){
		used[i]=0;
	}
	dfst(1);
	if(!ver){
		vector<int> v;
		for(int i=1;i<=n;i++){
			v.push_back(0);
		}
		return v;
	}
	if(ok){
		used[ver]=1;
		cnt=0;
		dfs2(1,0);
		cnt=0;
		dfs2(ver,1);
	}
	else{
		used[ver]=1;
		cnt=0;
		dfs2(1,1);
		cnt=0;
		dfs2(ver,0);
	}
	vector<int> v;
	for(int i=1;i<=n;i++){
		if(!ans[i]){
			ans[i]=3;
		}
		v.push_back(ans[i]);
	}
	return v;
}

Compilation message (stderr)

split.cpp: In function 'void dfs(int, int)':
split.cpp:67:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   67 |  used[v]=sz[v]=1;
      |          ~~~~~^~
split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:142:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  142 |  for(int i=0;i<p.size();i++){
      |              ~^~~~~~~~~
split.cpp:140:13: warning: variable 'pos' set but not used [-Wunused-but-set-variable]
  140 |  int mn=1e9,pos=0;
      |             ^~~

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