Submission #987444

#	Time	Username	Problem	Language	Result	Execution time	Memory
987444		Pyqe	Longest Trip (IOI23_longesttrip)	C++17	5 / 100	798 ms	4696 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"

using namespace std;

long long n,nn[2],dh[100069],pr[100069],ex[2][100069],tmp[100069],sq[100069],zs;
bitset<100069> vtd;

inline bool qr(vector<long long> v,vector<long long> v2)
{
	long long i,sz;
	vector<int> cv,cv2;
	
	sz=v.size();
	for(i=0;i<sz;i++)
	{
		cv.push_back(v[i]-1);
	}
	sz=v2.size();
	for(i=0;i<sz;i++)
	{
		cv2.push_back(v2[i]-1);
	}
	return are_connected(cv,cv2);
}

void dfs(long long x)
{
	long long i;
	
	vtd[x]=1;
	for(i=1;i<=n;i++)
	{
		if(!vtd[i]&&!qr({x},{i}))
		{
			dh[i]=dh[x]+1;
			pr[i]=x;
			dfs(i);
		}
	}
}

bool cmdh(long long x,long long y)
{
	return dh[x]<dh[y];
}

vector<int> longest_trip(int on,int d)
{
	long long i,ii,jj,k,l,sz,e,lh,rh,md,zz;
	vector<long long> cv,cv2;
	vector<int> ret;
	
	n=on;
	vtd.reset();
	for(ii=0;ii<2;ii++)
	{
		nn[ii]=0;
	}
	for(i=1;i<=n;i++)
	{
		if(!vtd[i])
		{
			dh[i]=0;
			dfs(i);
		}
		e=dh[i]%2;
		nn[e]++;
		ex[e][nn[e]]=i;
	}
	for(ii=0;ii<2;ii++)
	{
		sort(ex[ii]+1,ex[ii]+nn[ii]+1,cmdh);
		sz=0;
		l=-1;
		vtd.reset();
		for(i=nn[ii];i;i--)
		{
			k=ex[ii][i];
			if(l==-1)
			{
				l=k;
			}
			else if(dh[k]!=dh[l])
			{
				l=pr[pr[l]];
				sz++;
				tmp[sz]=l;
				vtd[l]=1;
			}
			if(!vtd[k])
			{
				sz++;
				tmp[sz]=k;
				l=k;
			}
		}
		for(i=1;i<=sz;i++)
		{
			ex[ii][i]=tmp[i];
		}
	}
	zs=0;
	for(i=1;i<=nn[0];i++)
	{
		cv.push_back(ex[0][i]);
	}
	for(i=1;i<=nn[1];i++)
	{
		cv2.push_back(ex[1][i]);
	}
	if(!nn[1]||!qr(cv,cv2))
	{
		e=nn[1]>nn[0];
		for(i=1;i<=nn[e];i++)
		{
			zs++;
			sq[zs]=ex[e][i];
		}
	}
	else
	{
		for(ii=0;ii<2;ii++)
		{
			k=ex[0][1];
			for(jj=0;jj<2;jj++)
			{
				l=ex[1][1];
				if(!zs&&qr({k},{l}))
				{
					for(i=nn[0];i;i--)
					{
						zs++;
						sq[zs]=ex[0][i];
					}
					for(i=1;i<=nn[1];i++)
					{
						zs++;
						sq[zs]=ex[1][i];
					}
				}
				reverse(ex[1]+1,ex[1]+nn[1]+1);
			}
			reverse(ex[0]+1,ex[0]+nn[0]+1);
		}
		if(!zs)
		{
			for(ii=0;ii<2;ii++)
			{
				cv2.clear();
				for(i=1;i<=nn[!ii];i++)
				{
					cv2.push_back(ex[!ii][i]);
				}
				for(lh=1,rh=nn[ii];lh<=rh;)
				{
					md=(lh+rh)/2;
					cv.clear();
					for(i=1;i<=md;i++)
					{
						cv.push_back(ex[ii][i]);
					}
					if(qr(cv,cv2))
					{
						zz=md;
						rh=md-1;
					}
					else
					{
						lh=md+1;
					}
				}
				k=zz;
				swap(k,l);
			}
			for(i=k+1;i<=nn[0];i++)
			{
				zs++;
				sq[zs]=ex[0][i];
			}
			for(i=1;i<=k;i++)
			{
				zs++;
				sq[zs]=ex[0][i];
			}
			for(i=l;i<=nn[1];i++)
			{
				zs++;
				sq[zs]=ex[1][i];
			}
			for(i=1;i<l;i++)
			{
				zs++;
				sq[zs]=ex[1][i];
			}
		}
	}
	for(i=1;i<=zs;i++)
	{
		ret.push_back(sq[i]-1);
	}
	return ret;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:194:11: warning: 'zz' may be used uninitialized in this function [-Wmaybe-uninitialized]
  194 |     sq[zs]=ex[1][i];
      |     ~~~~~~^~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 60