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Submission #778107

# Submission time Handle Problem Language Result Execution time Memory
778107 2023-07-10T06:24:00 Z CSQ31 Simurgh (IOI17_simurgh) C++17
70 / 100
 440 ms 13348 KB 
#include "simurgh.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
typedef long long int ll;
typedef pair<int,int> pii;
const int MAXN = 2e5;
int par[MAXN],szz[MAXN],good[MAXN],tree[MAXN];
vector<pii>adj[MAXN],ed;
int find(int x){
	if(x==par[x])return x;
	return par[x] = find(par[x]);
}
bool unite(int a,int b){
	a = find(a);
	b = find(b);
	if(a==b)return 0;
	if(szz[a] > szz[b])swap(a,b);
	par[a] = b;
	szz[b]+=szz[a];
	return 1;
}
void init(int n){
	for(int i=0;i<n;i++){
		par[i] = i;
		szz[i] = 1;
	}
}
set<int>edges;
vector<int>edge;
int nn;
bool debug = 0;
int Q = 0;
int ask(){
	Q++;
	assert(Q<=30000);
	vector<int>r;
	if(edges.empty())for(int x:edge)r.pb(x);
	else for(int x:edges)r.pb(x);
	if(debug)assert(sz(r)==nn-1);
	return count_common_roads(r);
}

pii p[MAXN];
int dep[MAXN],vis[MAXN],glob;
void dfs(int v,int u){
	vis[v] = 1;
	for(pii z:adj[v]){
		int x = z.fi;
		int id = z.se;
		if(vis[x] || x==u)continue;
		tree[id] = 1;
		edges.insert(id);
		dep[x] = dep[v]+1;
		p[x] = {v,id};
		dfs(x,v);
	}
}
void dfs2(int v,int u){
	
	for(pii z:adj[v]){
		int x = z.fi;
		int id = z.se;
		if(tree[id]){
			if(x!=u)dfs2(x,v);
			continue;
		}
		if(dep[x] > dep[v])continue; //go downwards
		
		vector<int>path,res;
		int cur = v;
		while(cur != x){
			path.pb(p[cur].se);
			cur = p[cur].fi;
		}
		//for(int e:path)cout<<e<<" ";
		//cout<<'\n';
		int have = 0;
		for(int e:path)have += (good[e] == -1);
		if(!have)continue; //if all tree edge part of this cycle is known,skip
		edges.insert(id);
		if(have == sz(path)){ //everything is unknown
			//cout<<"case 1"<<'\n';
			for(int e:path){
				edges.erase(e);
				res.pb(ask());
				edges.insert(e);
			}
			path.pb(id);
			res.pb(glob);
			int s = sz(path);
			for(int i=0;i<s;i++){
				int j = (i+s-1) % s;
				if(res[i] == res[j])continue;
				good[path[i]] = 1;
				good[path[j]] = 0;
				if(res[i] > res[j])swap(good[path[i]],good[path[j]]);
			}
			for(int i=0;i<s;i++){
				int j = (i+s-1) % s;
				if(good[path[j]] >= 0 && res[i] == res[j])good[path[i]] = good[path[j]];
			}
			for(int i=s-1;i>=0;i--){
				int j = (i+1) % s;
				if(good[path[j]] >= 0 && res[i] == res[j])good[path[i]] = good[path[j]];
			}
			for(int x:path){
				if(good[x] == -1)good[x] = 0;
			}
		}else{
			//cout<<"case 2"<<'\n';
			if(good[id] == -1){
				for(int e:path){
					if(good[e] == -1)continue;
					edges.erase(e);
					int res2 = ask();
					edges.insert(e);
					if(res2 == glob)good[id] = good[e];
					else if(res2 > glob)good[id] = 1; 
					else good[id] = 0;
					break;
				}
			}
			//cout<<good[id]<<'\n';
			for(int e:path){
				if(good[e] != -1)continue;
				edges.erase(e);
				int res2 = ask();
				edges.insert(e);
				if(res2 == glob)good[e] = good[id];
				else if(res2 > glob)good[e] = 0;
				else good[e] = 1;
			}
		}
		edges.erase(id);
	}
}
vector<int>e,solved;
void solve(int l,int r){
	if(l>r)return;
	init(nn);
	edge.clear();
	for(int i=l;i<=r;i++){
		if(unite(ed[e[i]].fi,ed[e[i]].se))edge.pb(e[i]);
	}
	int tot = 0;
	
	for(int i:solved){
		if(unite(ed[i].fi,ed[i].se)){
			edge.pb(i);
			tot+=good[i];
		}
		if(sz(edge)==nn-1)break;
		
	}
	int res = ask();
	edge.clear();
	if(res == tot){
		for(int i=l;i<=r;i++)good[e[i]] = 0;
		return;
	}else if(res == tot + r-l+1){
		for(int i=l;i<=r;i++)good[e[i]] = 1;
		return;
	}
	int mid = (l+r)/2;
	solve(l,mid);
	solve(mid+1,r);
	
	
}
mt19937 seed(chrono::high_resolution_clock::now().time_since_epoch().count());
vector<int> find_roads(int N,vector<int> u,vector<int> v) {
	nn = N;
	int n = N;
	int m = sz(u);
	for(int i=0;i<m;i++)ed.pb({v[i],u[i]});
	for(int i=0;i<m;i++){
		good[i] = -1;
		adj[u[i]].pb({v[i],i});
		adj[v[i]].pb({u[i],i});
	}
	dfs(0,-1);
	glob = ask();
	dfs2(0,-1);
	debug = 0;
	for(int x:edges){
		if(good[x]==-1)good[x] = 1; //this is a bridge	
	}
	int found = 0;
	vector<int>left;
	for(int i=0;i<m;i++){
		//cout<<good[i]<<" ";
		if(good[i]>=0){
			found+=good[i];
			solved.pb(i);
		}else left.pb(i);
	}
	shuffle(left.begin(),left.end(),seed);
	shuffle(solved.begin(),solved.end(),seed);
	edges.clear();
	/*
	for(int i=0;i<m;i++){
		if(good[i]>=0)continue;
		if(found==n-1)break;
		init(n);
		edge.clear();
		edge.pb(i);
		unite(v[i],u[i]);
		int tot = 0;
		for(int x:solved){
			if(unite(v[x],u[x])){
				edge.pb(x);
				tot+=good[x];
			}
		}
		if(ask() == tot)good[i] = 0;
		else{
			good[i] = 1;
			found++;
		}
		solved.pb(i);
	}*/
	while(sz(left) && found != n-1){
		init(n);
		e.clear();
		for(int x:left){
			if(unite(v[x],u[x]))e.pb(x);
		}
		solve(0,sz(e)-1);
		vector<int>tmp;
		for(int x:left){
			if(good[x] == -1)tmp.pb(x);
			else found+=good[x];
		}
		swap(left,tmp);
	}
	
	
	
	vector<int>ans;
	for(int i=0;i<m;i++){
		if(good[i] == 1)ans.pb(i);
	}
	return ans;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB correct
2 Correct 2 ms 4948 KB correct
3 Correct 2 ms 4948 KB correct
4 Correct 2 ms 4948 KB correct
5 Correct 2 ms 4948 KB correct
6 Correct 2 ms 4948 KB correct
7 Correct 2 ms 4948 KB correct
8 Correct 2 ms 4948 KB correct
9 Correct 2 ms 4948 KB correct
10 Correct 2 ms 4948 KB correct
11 Correct 2 ms 4948 KB correct
12 Correct 2 ms 4948 KB correct
13 Correct 2 ms 4948 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB correct
2 Correct 2 ms 4948 KB correct
3 Correct 2 ms 4948 KB correct
4 Correct 2 ms 4948 KB correct
5 Correct 2 ms 4948 KB correct
6 Correct 2 ms 4948 KB correct
7 Correct 2 ms 4948 KB correct
8 Correct 2 ms 4948 KB correct
9 Correct 2 ms 4948 KB correct
10 Correct 2 ms 4948 KB correct
11 Correct 2 ms 4948 KB correct
12 Correct 2 ms 4948 KB correct
13 Correct 2 ms 4948 KB correct
14 Correct 5 ms 5076 KB correct
15 Correct 4 ms 5076 KB correct
16 Correct 4 ms 5076 KB correct
17 Correct 5 ms 5120 KB correct
18 Correct 3 ms 5076 KB correct
19 Correct 4 ms 5076 KB correct
20 Correct 4 ms 5076 KB correct
21 Correct 4 ms 5076 KB correct
22 Correct 3 ms 5076 KB correct
23 Correct 4 ms 5076 KB correct
24 Correct 4 ms 4996 KB correct
25 Correct 2 ms 5024 KB correct
26 Correct 3 ms 5076 KB correct
27 Correct 3 ms 5100 KB correct
28 Correct 2 ms 5076 KB correct
29 Correct 2 ms 4948 KB correct
30 Correct 4 ms 5076 KB correct
31 Correct 3 ms 5008 KB correct
32 Correct 3 ms 5076 KB correct
33 Correct 3 ms 5076 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB correct
2 Correct 2 ms 4948 KB correct
3 Correct 2 ms 4948 KB correct
4 Correct 2 ms 4948 KB correct
5 Correct 2 ms 4948 KB correct
6 Correct 2 ms 4948 KB correct
7 Correct 2 ms 4948 KB correct
8 Correct 2 ms 4948 KB correct
9 Correct 2 ms 4948 KB correct
10 Correct 2 ms 4948 KB correct
11 Correct 2 ms 4948 KB correct
12 Correct 2 ms 4948 KB correct
13 Correct 2 ms 4948 KB correct
14 Correct 5 ms 5076 KB correct
15 Correct 4 ms 5076 KB correct
16 Correct 4 ms 5076 KB correct
17 Correct 5 ms 5120 KB correct
18 Correct 3 ms 5076 KB correct
19 Correct 4 ms 5076 KB correct
20 Correct 4 ms 5076 KB correct
21 Correct 4 ms 5076 KB correct
22 Correct 3 ms 5076 KB correct
23 Correct 4 ms 5076 KB correct
24 Correct 4 ms 4996 KB correct
25 Correct 2 ms 5024 KB correct
26 Correct 3 ms 5076 KB correct
27 Correct 3 ms 5100 KB correct
28 Correct 2 ms 5076 KB correct
29 Correct 2 ms 4948 KB correct
30 Correct 4 ms 5076 KB correct
31 Correct 3 ms 5008 KB correct
32 Correct 3 ms 5076 KB correct
33 Correct 3 ms 5076 KB correct
34 Correct 62 ms 6852 KB correct
35 Correct 59 ms 6720 KB correct
36 Correct 44 ms 6480 KB correct
37 Correct 10 ms 5076 KB correct
38 Correct 58 ms 6752 KB correct
39 Correct 60 ms 6632 KB correct
40 Correct 44 ms 6480 KB correct
41 Correct 62 ms 6768 KB correct
42 Correct 59 ms 6736 KB correct
43 Correct 18 ms 6152 KB correct
44 Correct 17 ms 5848 KB correct
45 Correct 17 ms 5972 KB correct
46 Correct 14 ms 5716 KB correct
47 Correct 13 ms 5460 KB correct
48 Correct 4 ms 5076 KB correct
49 Correct 6 ms 5148 KB correct
50 Correct 9 ms 5460 KB correct
51 Correct 25 ms 5984 KB correct
52 Correct 15 ms 5844 KB correct
53 Correct 19 ms 5804 KB correct
54 Correct 19 ms 6192 KB correct
55 Correct 21 ms 6000 KB correct
56 Correct 21 ms 5972 KB correct
57 Correct 20 ms 5932 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB correct
2 Correct 2 ms 4948 KB correct
3 Correct 225 ms 10596 KB correct
4 Correct 433 ms 12340 KB correct
5 Correct 409 ms 12456 KB correct
6 Correct 440 ms 12624 KB correct
7 Correct 425 ms 12640 KB correct
8 Correct 415 ms 12596 KB correct
9 Correct 394 ms 12508 KB correct
10 Correct 401 ms 12644 KB correct
11 Correct 412 ms 12512 KB correct
12 Correct 374 ms 12668 KB correct
13 Correct 3 ms 5012 KB correct
14 Correct 421 ms 12588 KB correct
15 Correct 422 ms 12624 KB correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB correct
2 Correct 2 ms 4948 KB correct
3 Correct 2 ms 4948 KB correct
4 Correct 2 ms 4948 KB correct
5 Correct 2 ms 4948 KB correct
6 Correct 2 ms 4948 KB correct
7 Correct 2 ms 4948 KB correct
8 Correct 2 ms 4948 KB correct
9 Correct 2 ms 4948 KB correct
10 Correct 2 ms 4948 KB correct
11 Correct 2 ms 4948 KB correct
12 Correct 2 ms 4948 KB correct
13 Correct 2 ms 4948 KB correct
14 Correct 5 ms 5076 KB correct
15 Correct 4 ms 5076 KB correct
16 Correct 4 ms 5076 KB correct
17 Correct 5 ms 5120 KB correct
18 Correct 3 ms 5076 KB correct
19 Correct 4 ms 5076 KB correct
20 Correct 4 ms 5076 KB correct
21 Correct 4 ms 5076 KB correct
22 Correct 3 ms 5076 KB correct
23 Correct 4 ms 5076 KB correct
24 Correct 4 ms 4996 KB correct
25 Correct 2 ms 5024 KB correct
26 Correct 3 ms 5076 KB correct
27 Correct 3 ms 5100 KB correct
28 Correct 2 ms 5076 KB correct
29 Correct 2 ms 4948 KB correct
30 Correct 4 ms 5076 KB correct
31 Correct 3 ms 5008 KB correct
32 Correct 3 ms 5076 KB correct
33 Correct 3 ms 5076 KB correct
34 Correct 62 ms 6852 KB correct
35 Correct 59 ms 6720 KB correct
36 Correct 44 ms 6480 KB correct
37 Correct 10 ms 5076 KB correct
38 Correct 58 ms 6752 KB correct
39 Correct 60 ms 6632 KB correct
40 Correct 44 ms 6480 KB correct
41 Correct 62 ms 6768 KB correct
42 Correct 59 ms 6736 KB correct
43 Correct 18 ms 6152 KB correct
44 Correct 17 ms 5848 KB correct
45 Correct 17 ms 5972 KB correct
46 Correct 14 ms 5716 KB correct
47 Correct 13 ms 5460 KB correct
48 Correct 4 ms 5076 KB correct
49 Correct 6 ms 5148 KB correct
50 Correct 9 ms 5460 KB correct
51 Correct 25 ms 5984 KB correct
52 Correct 15 ms 5844 KB correct
53 Correct 19 ms 5804 KB correct
54 Correct 19 ms 6192 KB correct
55 Correct 21 ms 6000 KB correct
56 Correct 21 ms 5972 KB correct
57 Correct 20 ms 5932 KB correct
58 Correct 2 ms 4948 KB correct
59 Correct 2 ms 4948 KB correct
60 Correct 225 ms 10596 KB correct
61 Correct 433 ms 12340 KB correct
62 Correct 409 ms 12456 KB correct
63 Correct 440 ms 12624 KB correct
64 Correct 425 ms 12640 KB correct
65 Correct 415 ms 12596 KB correct
66 Correct 394 ms 12508 KB correct
67 Correct 401 ms 12644 KB correct
68 Correct 412 ms 12512 KB correct
69 Correct 374 ms 12668 KB correct
70 Correct 3 ms 5012 KB correct
71 Correct 421 ms 12588 KB correct
72 Correct 422 ms 12624 KB correct
73 Correct 3 ms 4948 KB correct
74 Incorrect 371 ms 13348 KB WA in grader: NO
75 Halted 0 ms 0 KB -