oj.uz

Submission #68687

# Submission time Handle Problem Language Result Execution time Memory
68687 2018-08-18T05:43:31 Z zscoder Simurgh (IOI17_simurgh) C++17
70 / 100
 361 ms 17656 KB 
#include "simurgh.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
 
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> pbds;

struct edge
{
	int to, id;
	edge(int _to, int _id) : to(_to),id(_id){}
};

vector<edge> adj[555];
int timer;
int in[555];
int royal[555555];
int par[555];
int paredge[555];
bool vis[555];
int backedge[555];
int low[555];
vector<ii> T[555];
vector<int> S;

void prep(int u=0, int p=-1)
{
	in[u]=timer++; par[u]=p; vis[u]=1; low[u]=in[u];
	for(auto X:adj[u])
	{
		int v=X.to; int lab=X.id;
		if(v==p) continue;
		if(vis[v])
		{
			if(in[v]<low[u])
			{
				low[u]=in[v];
				backedge[u]=lab;
			}
		}
		else
		{
			S.pb(lab); paredge[v]=lab;
			//cerr<<"TREE EDGE "<<u<<' '<<v<<'\n'; 
			T[u].pb(mp(v,lab)); T[v].pb(mp(u,lab));
			prep(v,u);
			if(low[v]<low[u])
			{
				low[u]=low[v];
				backedge[u]=backedge[v];
			}
		}
	}
}

int query(int u, int v) //del edge u, add edge v
{
	vi V;
	for(int x:S)
	{
		if(x!=u) V.pb(x);
	}
	V.pb(v);
	/*
	cerr<<"QUERY\n";
	for(int v:V)
	{
		cerr<<v<<' ';
	}
	cerr<<'\n';
	*/
	return count_common_roads(V);
}
vector<ii> edges;

int ask_forest(vector<int> E)
{
	vi ex;
	for(int z:E)
	{
		ii x=edges[z];
		ex.pb(x.fi); ex.pb(x.se); 
	}
	queue<int> q;
	bitset<522> used; used.reset();
	for(int x:ex) used.set(x,1);
	for(int i=0;i<511;i++){if(used[i]) q.push(i);}
	int extra=0;
	vi vec=E;
	while(!q.empty())
	{
		int u=q.front(); q.pop();
		for(ii X:T[u])
		{
			int v=X.fi; int lab=X.se;
			if(used[v]) continue;
			extra+=royal[lab]; vec.pb(lab);
			q.push(v); used.set(v,1);
		}
	}
	return count_common_roads(vec)-extra;
}

void solve(vi V)
{
	if(V.empty()) return ;
	int ans = ask_forest(V);
	//cerr<<"ASK\n";
	//for(int x:V) cerr<<x<<' ';
	//cerr<<'\n';
	//cerr<<"ANS : "<<ans<<'\n';
	if(ans==0) return ;
	int n=V.size();
	if(n==1)
	{
		royal[V[0]]=1; return ;
	}
	vi L,R;
	for(int i=0;i<n/2;i++) L.pb(V[i]);
	for(int i=n/2;i<n;i++) R.pb(V[i]);
	solve(L);solve(R);
}

std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) 
{
	vi ans; int m=u.size();
	for(int i=0;i<m;i++) 
	{
		edges.pb(mp(u[i],v[i]));
		adj[u[i]].pb(edge(v[i],i)); adj[v[i]].pb(edge(u[i],i));
	}
	for(int i=0;i<n;i++) backedge[i]=-1;
	prep();
	for(int i=0;i<m;i++) royal[i]=-1;
	int tree_common = count_common_roads(S);
	vi backedges;
	for(int i=0;i<n;i++)
	{
		if(backedge[i]!=-1)
		{
			int x=u[backedge[i]]; int y=v[backedge[i]];
			if(in[x]<in[y]) swap(x,y);
			//cerr<<"BACK EDGE "<<i<<' '<<x<<' '<<y<<'\n';
			//x is grandchild of y
			vi path;
			while(x!=y)
			{
				path.pb(paredge[x]); x=par[x];
			}
			int known=-1;
			for(int e:path)
			{
				if(royal[e]!=-1) 
				{
					known=e;
					break;
				}
			}
			if(known==-1) //if no known edge, do the entire cycle
			{
				vi arr(int(path.size()));
				
				int exnonzero=-1;
				for(int j=0;j<path.size();j++)
				{
					arr[j]=query(path[j],backedge[i])-tree_common;
					if(arr[j]!=0) exnonzero=j;
				}
				
				//all 0 => none of them is part of tree because it's a cycle
				if(exnonzero==-1)
				{
					for(int v:path) royal[v]=0;
					royal[backedge[i]]=0;
				}
				else
				{
					if(arr[exnonzero]==1) //meaning backedge[i] is good
					{
						royal[backedge[i]]=1;
						for(int i=0;i<path.size();i++)
						{
							if(arr[i]==1) royal[path[i]]=0;
							else royal[path[i]]=1;
						}
					}
					else
					{
						royal[backedge[i]]=0;
						for(int i=0;i<path.size();i++)
						{
							if(arr[i]==0) royal[path[i]]=0;
							else royal[path[i]]=1;
						}
					}
				}
				/*
				cerr<<"RESULT : \n";
				for(int v:path) cerr<<v<<' '<<royal[v]<<'\n';
				cerr<<backedge[i]<<' '<<royal[backedge[i]]<<'\n';
				cerr<<'\n';
				*/
			}
			else //known is a known tree edge
			{
				int v = query(known, backedge[i]) - tree_common;
				v+=royal[known]; royal[backedge[i]]=v;
				for(int e:path)
				{
					if(royal[e]==-1)
					{
						int val = tree_common-query(e,backedge[i]);
						val+=royal[backedge[i]];
						royal[e]=val;
					}
				}
				/*
				cerr<<"RESULT : \n";
				for(int v:path) cerr<<v<<' '<<royal[v]<<'\n';
				cerr<<backedge[i]<<' '<<royal[backedge[i]]<<'\n';
				cerr<<'\n';
				*/
			}
		}
	}
	for(int e:S)
	{
		if(royal[e]==-1) royal[e]=1; //because it is a bridge
	}
	//now we should have determined the affinity of all the tree edges
	//optimize this part to nlogn
	/*
	for(int i=0;i<m;i++)
	{
		if(royal[i]==-1)
		{
			int x=u[i]; int y=v[i];
			if(in[x]<in[y]) swap(x,y);
			//x is a grandchild of y
			int v = query(paredge[x], i) - tree_common;
			v+=royal[paredge[x]];
			royal[i]=v;
		}
	}
	*/
	for(int i=0;i<m;i++)
	{
		if(royal[i]==-1) royal[i]=0;
	}
	for(int i=0;i<n;i++)
	{
		vi V;
		for(edge v:adj[i])
		{
			if(v.to>i) V.pb(v.id);
		}
		solve(V);
	}
	for(int i=0;i<m;i++)
	{
		if(royal[i]) ans.pb(i);
	}
	return ans;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:176:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=0;j<path.size();j++)
                 ~^~~~~~~~~~~~
simurgh.cpp:193:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i=0;i<path.size();i++)
                   ~^~~~~~~~~~~~
simurgh.cpp:202:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i=0;i<path.size();i++)
                   ~^~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB correct
2 Correct 3 ms 376 KB correct
3 Correct 3 ms 564 KB correct
4 Correct 2 ms 564 KB correct
5 Correct 3 ms 564 KB correct
6 Correct 3 ms 564 KB correct
7 Correct 3 ms 640 KB correct
8 Correct 2 ms 640 KB correct
9 Correct 2 ms 640 KB correct
10 Correct 3 ms 640 KB correct
11 Correct 3 ms 640 KB correct
12 Correct 3 ms 640 KB correct
13 Correct 2 ms 640 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB correct
2 Correct 3 ms 376 KB correct
3 Correct 3 ms 564 KB correct
4 Correct 2 ms 564 KB correct
5 Correct 3 ms 564 KB correct
6 Correct 3 ms 564 KB correct
7 Correct 3 ms 640 KB correct
8 Correct 2 ms 640 KB correct
9 Correct 2 ms 640 KB correct
10 Correct 3 ms 640 KB correct
11 Correct 3 ms 640 KB correct
12 Correct 3 ms 640 KB correct
13 Correct 2 ms 640 KB correct
14 Correct 5 ms 640 KB correct
15 Correct 4 ms 704 KB correct
16 Correct 6 ms 704 KB correct
17 Correct 5 ms 704 KB correct
18 Correct 4 ms 704 KB correct
19 Correct 6 ms 772 KB correct
20 Correct 4 ms 772 KB correct
21 Correct 4 ms 772 KB correct
22 Correct 4 ms 772 KB correct
23 Correct 4 ms 772 KB correct
24 Correct 4 ms 772 KB correct
25 Correct 3 ms 772 KB correct
26 Correct 4 ms 772 KB correct
27 Correct 4 ms 772 KB correct
28 Correct 4 ms 772 KB correct
29 Correct 4 ms 772 KB correct
30 Correct 5 ms 772 KB correct
31 Correct 5 ms 772 KB correct
32 Correct 5 ms 772 KB correct
33 Correct 4 ms 772 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB correct
2 Correct 3 ms 376 KB correct
3 Correct 3 ms 564 KB correct
4 Correct 2 ms 564 KB correct
5 Correct 3 ms 564 KB correct
6 Correct 3 ms 564 KB correct
7 Correct 3 ms 640 KB correct
8 Correct 2 ms 640 KB correct
9 Correct 2 ms 640 KB correct
10 Correct 3 ms 640 KB correct
11 Correct 3 ms 640 KB correct
12 Correct 3 ms 640 KB correct
13 Correct 2 ms 640 KB correct
14 Correct 5 ms 640 KB correct
15 Correct 4 ms 704 KB correct
16 Correct 6 ms 704 KB correct
17 Correct 5 ms 704 KB correct
18 Correct 4 ms 704 KB correct
19 Correct 6 ms 772 KB correct
20 Correct 4 ms 772 KB correct
21 Correct 4 ms 772 KB correct
22 Correct 4 ms 772 KB correct
23 Correct 4 ms 772 KB correct
24 Correct 4 ms 772 KB correct
25 Correct 3 ms 772 KB correct
26 Correct 4 ms 772 KB correct
27 Correct 4 ms 772 KB correct
28 Correct 4 ms 772 KB correct
29 Correct 4 ms 772 KB correct
30 Correct 5 ms 772 KB correct
31 Correct 5 ms 772 KB correct
32 Correct 5 ms 772 KB correct
33 Correct 4 ms 772 KB correct
34 Correct 72 ms 1912 KB correct
35 Correct 65 ms 1912 KB correct
36 Correct 68 ms 1912 KB correct
37 Correct 26 ms 1912 KB correct
38 Correct 77 ms 1912 KB correct
39 Correct 64 ms 1912 KB correct
40 Correct 52 ms 1912 KB correct
41 Correct 71 ms 1944 KB correct
42 Correct 71 ms 1944 KB correct
43 Correct 42 ms 1944 KB correct
44 Correct 43 ms 1944 KB correct
45 Correct 37 ms 1944 KB correct
46 Correct 35 ms 1944 KB correct
47 Correct 31 ms 1944 KB correct
48 Correct 11 ms 1944 KB correct
49 Correct 23 ms 1944 KB correct
50 Correct 29 ms 1944 KB correct
51 Correct 58 ms 1944 KB correct
52 Correct 36 ms 1944 KB correct
53 Correct 51 ms 1944 KB correct
54 Correct 45 ms 1944 KB correct
55 Correct 42 ms 1944 KB correct
56 Correct 43 ms 1944 KB correct
57 Correct 48 ms 1944 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 1944 KB correct
2 Correct 2 ms 1944 KB correct
3 Correct 211 ms 4596 KB correct
4 Correct 312 ms 7424 KB correct
5 Correct 325 ms 8184 KB correct
6 Correct 308 ms 9232 KB correct
7 Correct 212 ms 10208 KB correct
8 Correct 233 ms 11148 KB correct
9 Correct 306 ms 12080 KB correct
10 Correct 343 ms 13008 KB correct
11 Correct 317 ms 13936 KB correct
12 Correct 330 ms 14832 KB correct
13 Correct 2 ms 14832 KB correct
14 Correct 281 ms 15752 KB correct
15 Correct 361 ms 16724 KB correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB correct
2 Correct 3 ms 376 KB correct
3 Correct 3 ms 564 KB correct
4 Correct 2 ms 564 KB correct
5 Correct 3 ms 564 KB correct
6 Correct 3 ms 564 KB correct
7 Correct 3 ms 640 KB correct
8 Correct 2 ms 640 KB correct
9 Correct 2 ms 640 KB correct
10 Correct 3 ms 640 KB correct
11 Correct 3 ms 640 KB correct
12 Correct 3 ms 640 KB correct
13 Correct 2 ms 640 KB correct
14 Correct 5 ms 640 KB correct
15 Correct 4 ms 704 KB correct
16 Correct 6 ms 704 KB correct
17 Correct 5 ms 704 KB correct
18 Correct 4 ms 704 KB correct
19 Correct 6 ms 772 KB correct
20 Correct 4 ms 772 KB correct
21 Correct 4 ms 772 KB correct
22 Correct 4 ms 772 KB correct
23 Correct 4 ms 772 KB correct
24 Correct 4 ms 772 KB correct
25 Correct 3 ms 772 KB correct
26 Correct 4 ms 772 KB correct
27 Correct 4 ms 772 KB correct
28 Correct 4 ms 772 KB correct
29 Correct 4 ms 772 KB correct
30 Correct 5 ms 772 KB correct
31 Correct 5 ms 772 KB correct
32 Correct 5 ms 772 KB correct
33 Correct 4 ms 772 KB correct
34 Correct 72 ms 1912 KB correct
35 Correct 65 ms 1912 KB correct
36 Correct 68 ms 1912 KB correct
37 Correct 26 ms 1912 KB correct
38 Correct 77 ms 1912 KB correct
39 Correct 64 ms 1912 KB correct
40 Correct 52 ms 1912 KB correct
41 Correct 71 ms 1944 KB correct
42 Correct 71 ms 1944 KB correct
43 Correct 42 ms 1944 KB correct
44 Correct 43 ms 1944 KB correct
45 Correct 37 ms 1944 KB correct
46 Correct 35 ms 1944 KB correct
47 Correct 31 ms 1944 KB correct
48 Correct 11 ms 1944 KB correct
49 Correct 23 ms 1944 KB correct
50 Correct 29 ms 1944 KB correct
51 Correct 58 ms 1944 KB correct
52 Correct 36 ms 1944 KB correct
53 Correct 51 ms 1944 KB correct
54 Correct 45 ms 1944 KB correct
55 Correct 42 ms 1944 KB correct
56 Correct 43 ms 1944 KB correct
57 Correct 48 ms 1944 KB correct
58 Correct 2 ms 1944 KB correct
59 Correct 2 ms 1944 KB correct
60 Correct 211 ms 4596 KB correct
61 Correct 312 ms 7424 KB correct
62 Correct 325 ms 8184 KB correct
63 Correct 308 ms 9232 KB correct
64 Correct 212 ms 10208 KB correct
65 Correct 233 ms 11148 KB correct
66 Correct 306 ms 12080 KB correct
67 Correct 343 ms 13008 KB correct
68 Correct 317 ms 13936 KB correct
69 Correct 330 ms 14832 KB correct
70 Correct 2 ms 14832 KB correct
71 Correct 281 ms 15752 KB correct
72 Correct 361 ms 16724 KB correct
73 Correct 3 ms 16724 KB correct
74 Incorrect 285 ms 17656 KB WA in grader: NO
75 Halted 0 ms 0 KB -