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Submission #778291

# Submission time Handle Problem Language Result Execution time Memory
778291 2023-07-10T08:16:16 Z CSQ31 Simurgh (IOI17_simurgh) C++17
100 / 100
 112 ms 7064 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 QQ = 0;
int query(int u, int v) //del edge u, add edge v
{
QQ++;
	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, int cur)
{
	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]);
	int tmp = ask_forest(L);
	if(tmp>0) solve(L,tmp);
	if(cur-tmp>0) solve(R,cur-tmp);
}
 
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;
		}
	}
	*/
	assert(QQ<=1000);
	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);
		}
		if(V.empty()) continue;
		int ans = ask_forest(V);
		if(ans>0) solve(V,ans);
	}
	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:172:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  172 |     for(int j=0;j<path.size();j++)
      |                 ~^~~~~~~~~~~~
simurgh.cpp:189:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  189 |       for(int i=0;i<path.size();i++)
      |                   ~^~~~~~~~~~~~
simurgh.cpp:198:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  198 |       for(int i=0;i<path.size();i++)
      |                   ~^~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB correct
2 Correct 0 ms 340 KB correct
3 Correct 0 ms 340 KB correct
4 Correct 0 ms 340 KB correct
5 Correct 1 ms 340 KB correct
6 Correct 0 ms 340 KB correct
7 Correct 0 ms 340 KB correct
8 Correct 0 ms 340 KB correct
9 Correct 0 ms 340 KB correct
10 Correct 0 ms 340 KB correct
11 Correct 0 ms 340 KB correct
12 Correct 0 ms 340 KB correct
13 Correct 0 ms 340 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB correct
2 Correct 0 ms 340 KB correct
3 Correct 0 ms 340 KB correct
4 Correct 0 ms 340 KB correct
5 Correct 1 ms 340 KB correct
6 Correct 0 ms 340 KB correct
7 Correct 0 ms 340 KB correct
8 Correct 0 ms 340 KB correct
9 Correct 0 ms 340 KB correct
10 Correct 0 ms 340 KB correct
11 Correct 0 ms 340 KB correct
12 Correct 0 ms 340 KB correct
13 Correct 0 ms 340 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 1 ms 340 KB correct
18 Correct 1 ms 340 KB correct
19 Correct 2 ms 340 KB correct
20 Correct 2 ms 340 KB correct
21 Correct 1 ms 340 KB correct
22 Correct 1 ms 340 KB correct
23 Correct 2 ms 340 KB correct
24 Correct 1 ms 340 KB correct
25 Correct 1 ms 340 KB correct
26 Correct 1 ms 340 KB correct
27 Correct 1 ms 340 KB correct
28 Correct 1 ms 340 KB correct
29 Correct 1 ms 340 KB correct
30 Correct 1 ms 340 KB correct
31 Correct 1 ms 340 KB correct
32 Correct 1 ms 340 KB correct
33 Correct 1 ms 340 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB correct
2 Correct 0 ms 340 KB correct
3 Correct 0 ms 340 KB correct
4 Correct 0 ms 340 KB correct
5 Correct 1 ms 340 KB correct
6 Correct 0 ms 340 KB correct
7 Correct 0 ms 340 KB correct
8 Correct 0 ms 340 KB correct
9 Correct 0 ms 340 KB correct
10 Correct 0 ms 340 KB correct
11 Correct 0 ms 340 KB correct
12 Correct 0 ms 340 KB correct
13 Correct 0 ms 340 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 1 ms 340 KB correct
18 Correct 1 ms 340 KB correct
19 Correct 2 ms 340 KB correct
20 Correct 2 ms 340 KB correct
21 Correct 1 ms 340 KB correct
22 Correct 1 ms 340 KB correct
23 Correct 2 ms 340 KB correct
24 Correct 1 ms 340 KB correct
25 Correct 1 ms 340 KB correct
26 Correct 1 ms 340 KB correct
27 Correct 1 ms 340 KB correct
28 Correct 1 ms 340 KB correct
29 Correct 1 ms 340 KB correct
30 Correct 1 ms 340 KB correct
31 Correct 1 ms 340 KB correct
32 Correct 1 ms 340 KB correct
33 Correct 1 ms 340 KB correct
34 Correct 23 ms 1744 KB correct
35 Correct 22 ms 1616 KB correct
36 Correct 19 ms 1488 KB correct
37 Correct 9 ms 468 KB correct
38 Correct 26 ms 1744 KB correct
39 Correct 19 ms 1616 KB correct
40 Correct 18 ms 1376 KB correct
41 Correct 22 ms 1744 KB correct
42 Correct 23 ms 1744 KB correct
43 Correct 14 ms 1220 KB correct
44 Correct 12 ms 980 KB correct
45 Correct 13 ms 980 KB correct
46 Correct 11 ms 980 KB correct
47 Correct 8 ms 596 KB correct
48 Correct 4 ms 340 KB correct
49 Correct 6 ms 468 KB correct
50 Correct 8 ms 664 KB correct
51 Correct 13 ms 980 KB correct
52 Correct 12 ms 980 KB correct
53 Correct 12 ms 980 KB correct
54 Correct 13 ms 1236 KB correct
55 Correct 15 ms 1108 KB correct
56 Correct 17 ms 1108 KB correct
57 Correct 14 ms 1108 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB correct
2 Correct 0 ms 340 KB correct
3 Correct 66 ms 4412 KB correct
4 Correct 104 ms 6096 KB correct
5 Correct 104 ms 6112 KB correct
6 Correct 98 ms 6044 KB correct
7 Correct 70 ms 6048 KB correct
8 Correct 82 ms 6096 KB correct
9 Correct 100 ms 6048 KB correct
10 Correct 105 ms 6120 KB correct
11 Correct 102 ms 6112 KB correct
12 Correct 104 ms 6040 KB correct
13 Correct 0 ms 340 KB correct
14 Correct 88 ms 6052 KB correct
15 Correct 112 ms 6168 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB correct
2 Correct 0 ms 340 KB correct
3 Correct 0 ms 340 KB correct
4 Correct 0 ms 340 KB correct
5 Correct 1 ms 340 KB correct
6 Correct 0 ms 340 KB correct
7 Correct 0 ms 340 KB correct
8 Correct 0 ms 340 KB correct
9 Correct 0 ms 340 KB correct
10 Correct 0 ms 340 KB correct
11 Correct 0 ms 340 KB correct
12 Correct 0 ms 340 KB correct
13 Correct 0 ms 340 KB correct
14 Correct 1 ms 340 KB correct
15 Correct 1 ms 340 KB correct
16 Correct 1 ms 340 KB correct
17 Correct 1 ms 340 KB correct
18 Correct 1 ms 340 KB correct
19 Correct 2 ms 340 KB correct
20 Correct 2 ms 340 KB correct
21 Correct 1 ms 340 KB correct
22 Correct 1 ms 340 KB correct
23 Correct 2 ms 340 KB correct
24 Correct 1 ms 340 KB correct
25 Correct 1 ms 340 KB correct
26 Correct 1 ms 340 KB correct
27 Correct 1 ms 340 KB correct
28 Correct 1 ms 340 KB correct
29 Correct 1 ms 340 KB correct
30 Correct 1 ms 340 KB correct
31 Correct 1 ms 340 KB correct
32 Correct 1 ms 340 KB correct
33 Correct 1 ms 340 KB correct
34 Correct 23 ms 1744 KB correct
35 Correct 22 ms 1616 KB correct
36 Correct 19 ms 1488 KB correct
37 Correct 9 ms 468 KB correct
38 Correct 26 ms 1744 KB correct
39 Correct 19 ms 1616 KB correct
40 Correct 18 ms 1376 KB correct
41 Correct 22 ms 1744 KB correct
42 Correct 23 ms 1744 KB correct
43 Correct 14 ms 1220 KB correct
44 Correct 12 ms 980 KB correct
45 Correct 13 ms 980 KB correct
46 Correct 11 ms 980 KB correct
47 Correct 8 ms 596 KB correct
48 Correct 4 ms 340 KB correct
49 Correct 6 ms 468 KB correct
50 Correct 8 ms 664 KB correct
51 Correct 13 ms 980 KB correct
52 Correct 12 ms 980 KB correct
53 Correct 12 ms 980 KB correct
54 Correct 13 ms 1236 KB correct
55 Correct 15 ms 1108 KB correct
56 Correct 17 ms 1108 KB correct
57 Correct 14 ms 1108 KB correct
58 Correct 0 ms 340 KB correct
59 Correct 0 ms 340 KB correct
60 Correct 66 ms 4412 KB correct
61 Correct 104 ms 6096 KB correct
62 Correct 104 ms 6112 KB correct
63 Correct 98 ms 6044 KB correct
64 Correct 70 ms 6048 KB correct
65 Correct 82 ms 6096 KB correct
66 Correct 100 ms 6048 KB correct
67 Correct 105 ms 6120 KB correct
68 Correct 102 ms 6112 KB correct
69 Correct 104 ms 6040 KB correct
70 Correct 0 ms 340 KB correct
71 Correct 88 ms 6052 KB correct
72 Correct 112 ms 6168 KB correct
73 Correct 1 ms 340 KB correct
74 Correct 111 ms 6088 KB correct
75 Correct 105 ms 6888 KB correct
76 Correct 54 ms 2780 KB correct
77 Correct 108 ms 7064 KB correct
78 Correct 104 ms 7040 KB correct
79 Correct 106 ms 7060 KB correct
80 Correct 106 ms 6860 KB correct
81 Correct 84 ms 6220 KB correct
82 Correct 111 ms 6884 KB correct
83 Correct 80 ms 4012 KB correct
84 Correct 60 ms 4812 KB correct
85 Correct 57 ms 4536 KB correct
86 Correct 57 ms 3032 KB correct
87 Correct 52 ms 2512 KB correct
88 Correct 44 ms 1860 KB correct
89 Correct 37 ms 1780 KB correct
90 Correct 41 ms 1616 KB correct
91 Correct 20 ms 556 KB correct
92 Correct 18 ms 440 KB correct
93 Correct 67 ms 4512 KB correct
94 Correct 49 ms 2952 KB correct
95 Correct 52 ms 3032 KB correct
96 Correct 49 ms 1704 KB correct
97 Correct 38 ms 1848 KB correct
98 Correct 41 ms 2512 KB correct
99 Correct 41 ms 1844 KB correct
100 Correct 29 ms 772 KB correct
101 Correct 19 ms 476 KB correct
102 Correct 71 ms 3788 KB correct
103 Correct 71 ms 3768 KB correct
104 Correct 72 ms 3736 KB correct
105 Correct 66 ms 3736 KB correct