Submission #861317

#	Time	Username	Problem	Language	Result	Execution time	Memory
861317		Faisal_Saqib	Pipes (CEOI15_pipes)	C++17	0 / 100	871 ms	65536 KiB

pipes

#include <iostream>
#include <algorithm>
#include <climits>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <vector>

using namespace std;

const int MAXN=1e5+1;
const int LG=17;
int pa[MAXN][LG];
int par[MAXN];
int par1[MAXN];
int h[MAXN];
int Up[MAXN];
bool vis[MAXN];
vector<int> ma[MAXN];
vector<int> comp2[MAXN];
int get1(int a)
{
	return ((par1[a]==a)?a:par1[a]=get1(par1[a]));
}
void join1(int a,int b)
{
	a=get1(a);
	b=get1(b);
	if(a!=b)
		par1[a]=b;
}
int get(int a)
{
	return ((par[a]==a)?a:par[a]=get(par[a]));
}
bool join(int a,int b)
{
	int oa=a;
	int ob=b;
	a=get(a);
	b=get(b);
	if(a!=b)
	{
		par[a]=b;
		return 1;
	}
	join1(oa,ob);
	return 0;
}
void dfs(int x,int p=1)
{
	pa[x][0]=p;
	for(int j=1;j<LG;j++)
		pa[x][j]=pa[pa[x][j-1]][j-1];
	h[x]=h[p]+1;
	for(auto y:ma[x])
		if(y!=p)
			dfs(y,x);
}
int lca(int x,int y)
{
	if(h[x]>h[y])
		swap(x,y);
	for(int j=LG-1;j>=0;j--)
		if(h[x]<=h[pa[y][j]])
			y=pa[y][j];
	if(x==y)
		return x;
	for(int j=LG-1;j>=0;j--)
		if(pa[x][j]!=pa[y][j])
		{
			x=pa[x][j];
			y=pa[y][j];
		}
	return pa[x][0];
}
void solve(int x,int p=-1)
{
	vis[x]=1;
	for(auto y:ma[x])
	{
		if(y!=p)
		{
			solve(y,x);
		}
	}
	for(auto y:ma[x])
	{
		if(y!=p)
		{
			if(h[Up[x]]>h[Up[y]])
			{
				Up[x]=Up[y];
			}
			if(Up[y]==y)
			{
				cout<<x<<' '<<y<<endl;
			}
		}
	}
	for(auto y:comp2[x])
	{
		int c=lca(x,y);
		if(h[Up[x]]>h[c])
		{
			Up[x]=c;
		}
		if(h[Up[y]]>h[c])
		{
			Up[y]=c;
		}
	}
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
    int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    	par[i]=par1[i]=Up[i]=i;
    for(int i=0;i<m;i++)
    {
    	int x,y;
    	cin>>x>>y;
    	if(join(x,y))
    	{
    		ma[x].push_back(y);
    		ma[y].push_back(x);
    	}
    }
    for(int i=1;i<=n;i++)
    	if(pa[i][0]==0)
		    dfs(i);
    for(int i=1;i<=n;i++)
    	if(h[i]>h[get1(i)])
    		par1[get1(i)]=par1[i]=i;
    for(int i=1;i<=n;i++)
    	comp2[get1(i)].push_back(i);
    for(int i=1;i<=n;i++)
    	if(!vis[i])
		    solve(i);
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10