Submission #891507

#	Time	Username	Problem	Language	Result	Execution time	Memory
891507		Faisal_Saqib	Split the Attractions (IOI19_split)	C++17	40 / 100	74 ms	23096 KiB

split

#include <vector>
#include <set>
#include <algorithm>
using namespace std;
const int N=2e5+1;
vector<int> ma[N];
int color[N],in[N],sz[N];
bool vis[N];
set<int> one,two;
int n;
void dfs_sz(int x,int p=-1)
{
	sz[x]=1;
	for(auto y:ma[x])
	{
		if(y!=p)
		{
			dfs_sz(y,x);
			sz[x]+=sz[y];
		}
	}
}
bool asd=0;
void take(int x,int cnt,bool sp)
{
	vis[x]=1;
	if(sp)
	{
		if(two.size()<cnt)
		{
			two.insert(x);
		}
	}
	else
	{
		if(one.size()<cnt)
		{
			one.insert(x);
		}
	}
	for(auto y:ma[x])
	{
		if(!vis[y])
		{
			take(y,cnt,sp);
		}
	}
}
void find_edge(int x,int a,int b,int p=-1)
{
	vis[x]=1;
	if(asd)
		return;
	for(auto y:ma[x])
	{
		if(!vis[y])
		{
			if(asd)
			{
				return;
			}
			if(sz[y]>=b and (n-sz[y])>=a)
			{
				one.clear();
				two.clear();
				for(int i=1;i<=n;i++)
					vis[i]=0;
				vis[x]=1;
				take(y,b,1);
				for(int i=1;i<=n;i++)
					vis[i]=0;
				vis[y]=1;
				take(x,a,0);
				asd=1;
				return;
			}
			if(sz[y]>=a and (n-sz[y])>=b)
			{
				one.clear();
				two.clear();
				for(int i=1;i<=n;i++)
					vis[i]=0;
				vis[x]=1;
				take(y,a,0);
				for(int i=1;i<=n;i++)
					vis[i]=0;
				vis[y]=1;
				take(x,b,1);
				asd=1;
				return;
			}
			sz[x]-=sz[y];
			sz[y]+=sz[x];
			find_edge(y,a,b,x);
			sz[y]-=sz[x];
			sz[x]+=sz[y];
		}
	}
}
void dfs(int x,int a,int b)
{
	if(one.size()<a)
	{
		one.insert(x);
	}
	else if(two.size()<b)
	{
		two.insert(x);
	}
	vis[x]=1;
	for(auto y:ma[x])
	{
		if(!vis[y])
		{
			dfs(y,a,b);
		}
	}
}
vector<int> find_split(int n1, int a, int b, int c, vector<int> p, vector<int> q)
{
	n=n1;
	// Swap a,b,c to make a<=b<=c hold and assign new color to each
	vector<pair<int,int>> aps;
	aps.push_back({a,1});
	aps.push_back({b,2});
	aps.push_back({c,3});
	sort(begin(aps),end(aps));
	int colora,colorb,colorc;
	a=aps[0].first;
	colora=aps[0].second;
	b=aps[1].first;
	colorb=aps[1].second;
	c=aps[2].first;
	colorc=aps[2].second;
	// Sorting done
	// Adding Edges
	int m=p.size();
	int mx=0;
	for(int j=0;j<m;j++)
	{
		p[j]++;
		q[j]++;
		ma[p[j]].push_back(q[j]);
		ma[q[j]].push_back(p[j]);
		in[p[j]]++;
		in[q[j]]++;
		mx=max(mx,in[p[j]]);
		mx=max(mx,in[q[j]]);
	}
	// Edges added
	if(m==(n-1))
	{
		// Simple as eating ice cream
		// Find an edge such that if remove it then the two component have size1,size2
		// size1>=size2
		// size1>=a and size2>=b
		// then we can make answer
		dfs_sz(1);
		find_edge(1,a,b);
		for(int i=1;i<=n;i++)
		{
			color[i]=colorc;
		}
		for(auto i:one)
		{
			color[i]=colora;
		}
		for(auto i:two)
		{
			color[i]=colorb;
		}
		vector<int> ans;
		for(int i=1;i<=n;i++)
		{
			if(!asd)
			{
				ans.push_back(0);
			}
			else
				ans.push_back(color[i]);
		}
		return ans;
	}
	if(a==1 or mx<=2)
	{
		bool pos=1;
		for(int j=1;j<=n;j++)
		{
			if(ma[j].size()==1)
			{
				dfs(j,a,b);
				pos=0;
				break;
			}
		}
		if(pos)
		{
			dfs(1,a,b);
		}
		for(int i=1;i<=n;i++)
		{
			color[i]=colorc;
		}
		for(auto i:two)
		{
			color[i]=colorb;
		}
		for(auto i:one)
		{
			color[i]=colora;
		}
		vector<int> ans;
		for(int i=1;i<=n;i++)
		{
			ans.push_back(color[i]);
		}
		return ans;
	}
	// exit(-1);
	return {};
}

Compilation message (stderr)

split.cpp: In function 'void take(int, int, bool)':
split.cpp:29:16: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |   if(two.size()<cnt)
      |      ~~~~~~~~~~^~~~
split.cpp:36:16: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   36 |   if(one.size()<cnt)
      |      ~~~~~~~~~~^~~~
split.cpp: In function 'void dfs(int, int, int)':
split.cpp:102:15: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  102 |  if(one.size()<a)
      |     ~~~~~~~~~~^~
split.cpp:106:20: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  106 |  else if(two.size()<b)
      |          ~~~~~~~~~~^~

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