Submission #49607

#	Time	Username	Problem	Language	Result	Execution time	Memory
49607		yogahmad	Simurgh (IOI17_simurgh)	C++14	30 / 100	241 ms	20256 KiB

simurgh

#include <bits/stdc++.h>
#include "simurgh.h"
#define f first
#define s second
#define pb push_back
#define mx 250003
#define ALL(x) x.begin(),x.end()
using namespace std;
int di[mx],M,idx,brp[505][505],level[mx];
bool sudah[mx];
int P[mx];
vector<pair<int,int>>cycle;
vector<int> r;
vector<int>g[mx];


void dfs(int now,int par=0,int lev=1){
	sudah[now]=true;
	level[now]=lev;
	for(auto i:g[now]){
		if(i==par)
			continue;
		if(!sudah[i]){
			P[i]=now;
			di[brp[now][i]]=idx++;
			r.pb(brp[now][i]);
			dfs(i,now,lev+1);
		}
		else if(level[i]<level[now]){
			cycle.pb({now,i});
		}
	}
}

bool cmp(pair<int,int>x,pair<int,int>y){
	return level[x.s]>level[y.s];
}
int par[mx];
int find(int aa){
	if(aa==par[aa])return aa;
	return par[aa]=find(par[aa]);
}
vector<int> find_roads(int N, vector<int> u, vector<int> v) {
	M=u.size();
	for(int i=0;i<M;i++){
		g[u[i]+1].pb(v[i]+1);
		g[v[i]+1].pb(u[i]+1);
		brp[u[i]+1][v[i]+1]=i;
		brp[v[i]+1][u[i]+1]=i;
	}
	for(int i=1;i<=N;i++){
		random_shuffle(ALL(g[i]));
	}
	memset(di,-1,sizeof di);
	dfs(1,0);
	vector<int>satu(N-1);
	int maks=count_common_roads(r);
	for(int i:r){
	//	cout<<u[i]<<" -> "<<v[i]<<"  --  "<<i<<endl;
	}
//	cout<<maks<<endl;
	sort(ALL(cycle),cmp);
	int cnt=0;
	cnt++;
//	debug(maks);
	for(auto i:cycle){
	//	cout<<i.f-1<<" -> "<<i.s-1<<endl;
		int dari=i.f,ke=i.s;
		int besar=0;
		while(dari!=ke){
		//	cout<<"ini "<<" "<<dari-1<<" "<<P[dari]-1<<endl;
			if(di[brp[dari][P[dari]]]!=-1){
				if(cnt==30000)
					break;
				int tmp=brp[dari][P[dari]];
				r[di[tmp]]=brp[i.f][i.s];
				for(int j=0;j<N;j++)
					par[j]=j;
				bool ya=true;
				for(int i:r){
					int x=find(u[i]);
					int y=find(v[i]);
					if(x==y){
						ya=false;
						break;
					}
					par[x]=y;
				}
				int sem=0;
				if(ya && cnt<30000)cnt++,sem=count_common_roads(r);
			//	debug(sem);
				if(sem>besar){
					satu=r;
					besar=sem;
				}
				r[di[tmp]]=brp[dari][P[dari]];
				if(besar>maks){
					break;
				}
			}
			dari=P[dari];
		}
		if(besar>maks){
			maks=besar;
			r=satu;
			memset(di,-1,sizeof di);
			for(int i=0;i<N-1;i++){
				di[r[i]]=i;
			}
		}
		if(cnt==30000)
			break;
	//	for(int i:r)cout<<i<<' ';
	//	cout<<endl;
	//	debug(maks);
	}
	assert(maks==N-1);
//	cout<<maks<<endl;
	return r;
}

Compilation message (stderr)

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:58:10: warning: unused variable 'i' [-Wunused-variable]
  for(int i:r){
          ^

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30