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Submission #565224

# Submission time Handle Problem Language Result Execution time Memory
565224 2022-05-20T13:33:39 Z jamezzz Simurgh (IOI17_simurgh) C++17
100 / 100
 533 ms 7488 KB 
#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
typedef pair<int,int> ii;

#define maxn 505

struct UFDS{
	int par[maxn],rnk[maxn];
	void init(int n){
		for(int i=0;i<n;++i)par[i]=i,rnk[i]=1;
	}
	int fp(int i){
		return (par[i]==i)?i:par[i]=fp(par[i]);
	}
	void join(int x,int y){
		x=fp(x),y=fp(y);
		if(x==y)return;
		if(rnk[x]<rnk[y])par[x]=y;
		else par[y]=x;
		if(rnk[x]==rnk[y])++rnk[x];
	}
}ufds;

int n,m,good[maxn*maxn],edge[maxn][maxn];
int par[maxn],depth[maxn],deg[maxn],done[maxn];
vector<int> AL[maxn];
vector<ii> EL,back_edge,tree_edge;

void dfs(int u){
	int far=u;
	for(int v:AL[u]){
		if(depth[v]==0){
			par[v]=u;
			depth[v]=depth[u]+1;
			dfs(v);
			tree_edge.pb({u,v});
		}
		else if(v!=par[u]&&depth[far]>depth[v])far=v;
	}
	back_edge.pb({u,far});
}

int count(vector<int> e){
	int num=0;
	ufds.init(n);
	vector<int> ask;
	for(int i:e){
		int u,v;
		tie(u,v)=EL[i];
		ufds.join(u,v);
		ask.pb(edge[u][v]);
	}
	for(auto[u,v]:tree_edge){
		if(ufds.fp(u)!=ufds.fp(v)){
			ufds.join(u,v);
			ask.pb(edge[u][v]);
			num+=good[edge[u][v]];
		}
	}
	return count_common_roads(ask)-num;
}

vector<int> find_roads(int _n,vector<int> u,vector<int> v){
	n=_n;m=u.size();
	memset(edge,-1,sizeof edge);
	memset(good,-1,sizeof good);
	for(int i=0;i<m;++i){
		AL[u[i]].pb(v[i]);
		AL[v[i]].pb(u[i]);
		edge[u[i]][v[i]]=edge[v[i]][u[i]]=i;
		EL.pb({u[i],v[i]});
	}
	
	depth[0]=1;
	dfs(0);
	
	for(auto[u,v]:back_edge){
		if(u==v)continue;
		vector<ii> edges;
		edges.pb({u,v});
		ufds.init(n);
		while(u!=v){
			edges.pb({u,par[u]});
			ufds.join(u,par[u]);
			u=par[u];
		}
		
		vector<ii> others;
		for(auto[u,v]:EL){
			if(ufds.fp(u)!=ufds.fp(v)){
				others.pb({u,v});
				ufds.join(u,v);
			}
		}
		
		vector<ii> res;
		bool have_ref=false;
		int ref_type=-1,ref_val=-1;
		for(auto[u,v]:edges){
			int id=edge[u][v];
			if(good[id]!=-1&&have_ref)continue;
			if(good[id]!=-1)have_ref=true;
			vector<int> ask;
			for(auto[u,v]:others)ask.pb(edge[u][v]);
			for(auto[x,y]:edges){
				if(x!=u||y!=v)ask.pb(edge[x][y]);
			}
			res.pb({count_common_roads(ask),id});
			
			if(good[id]!=-1)ref_type=good[id],ref_val=res.back().fi;
		}
		if(res.size()==0)continue;
		sort(res.begin(),res.end());
		int small=res[0].fi,big=res.back().fi;
		for(auto[x,i]:res){
			if(x==ref_val)good[i]=ref_type;
			else if(x==big)good[i]=0;
			else if(x==small)good[i]=1;
		}
	}
	
	for(auto[u,v]:tree_edge){
		int id=edge[u][v];
		if(good[id]==-1)good[id]=1;
	}
	
	for(int u=0;u<n;++u){
		vector<int> tmp;
		for(int v:AL[u])tmp.pb(edge[u][v]);
		deg[u]=count(tmp);
	}
	
	while(true){
		int u=-1;
		for(int i=0;i<n;++i){
			if(done[i]==0&&deg[i]==1)u=i;
		}
		if(u==-1)break;
		vector<int> e;
		for(int v:AL[u]){
			if(!done[v])e.pb(edge[u][v]);
		}
		int lo=0,hi=e.size()-1,mid,res;
		while(lo<=hi){
			mid=(lo+hi)>>1;
			vector<int> tmp;
			for(int i=0;i<=mid;++i)tmp.pb(e[i]);
			if(count(tmp)==1)res=mid,hi=mid-1;
			else lo=mid+1;
		}
		good[e[res]]=1;
		int v=EL[e[res]].fi;
		if(u==v)v=EL[e[res]].se;
		--deg[v];
		done[u]=1;
	}
	
	vector<int> ans;
	for(int i=0;i<m;++i){
		if(good[i]==1)ans.pb(i);
	}
	assert(count_common_roads(ans)==n-1);
	return ans;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:156:13: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
  156 |   good[e[res]]=1;
      |             ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2260 KB correct
2 Correct 1 ms 2260 KB correct
3 Correct 1 ms 2260 KB correct
4 Correct 1 ms 2260 KB correct
5 Correct 1 ms 2260 KB correct
6 Correct 1 ms 2260 KB correct
7 Correct 2 ms 2260 KB correct
8 Correct 2 ms 2260 KB correct
9 Correct 1 ms 2260 KB correct
10 Correct 1 ms 2260 KB correct
11 Correct 2 ms 2260 KB correct
12 Correct 1 ms 2260 KB correct
13 Correct 1 ms 2260 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2260 KB correct
2 Correct 1 ms 2260 KB correct
3 Correct 1 ms 2260 KB correct
4 Correct 1 ms 2260 KB correct
5 Correct 1 ms 2260 KB correct
6 Correct 1 ms 2260 KB correct
7 Correct 2 ms 2260 KB correct
8 Correct 2 ms 2260 KB correct
9 Correct 1 ms 2260 KB correct
10 Correct 1 ms 2260 KB correct
11 Correct 2 ms 2260 KB correct
12 Correct 1 ms 2260 KB correct
13 Correct 1 ms 2260 KB correct
14 Correct 4 ms 2296 KB correct
15 Correct 3 ms 2388 KB correct
16 Correct 3 ms 2388 KB correct
17 Correct 3 ms 2260 KB correct
18 Correct 2 ms 2260 KB correct
19 Correct 3 ms 2260 KB correct
20 Correct 3 ms 2260 KB correct
21 Correct 2 ms 2260 KB correct
22 Correct 2 ms 2260 KB correct
23 Correct 3 ms 2260 KB correct
24 Correct 2 ms 2260 KB correct
25 Correct 2 ms 2244 KB correct
26 Correct 3 ms 2260 KB correct
27 Correct 2 ms 2260 KB correct
28 Correct 2 ms 2244 KB correct
29 Correct 3 ms 2260 KB correct
30 Correct 2 ms 2260 KB correct
31 Correct 2 ms 2260 KB correct
32 Correct 2 ms 2260 KB correct
33 Correct 3 ms 2260 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2260 KB correct
2 Correct 1 ms 2260 KB correct
3 Correct 1 ms 2260 KB correct
4 Correct 1 ms 2260 KB correct
5 Correct 1 ms 2260 KB correct
6 Correct 1 ms 2260 KB correct
7 Correct 2 ms 2260 KB correct
8 Correct 2 ms 2260 KB correct
9 Correct 1 ms 2260 KB correct
10 Correct 1 ms 2260 KB correct
11 Correct 2 ms 2260 KB correct
12 Correct 1 ms 2260 KB correct
13 Correct 1 ms 2260 KB correct
14 Correct 4 ms 2296 KB correct
15 Correct 3 ms 2388 KB correct
16 Correct 3 ms 2388 KB correct
17 Correct 3 ms 2260 KB correct
18 Correct 2 ms 2260 KB correct
19 Correct 3 ms 2260 KB correct
20 Correct 3 ms 2260 KB correct
21 Correct 2 ms 2260 KB correct
22 Correct 2 ms 2260 KB correct
23 Correct 3 ms 2260 KB correct
24 Correct 2 ms 2260 KB correct
25 Correct 2 ms 2244 KB correct
26 Correct 3 ms 2260 KB correct
27 Correct 2 ms 2260 KB correct
28 Correct 2 ms 2244 KB correct
29 Correct 3 ms 2260 KB correct
30 Correct 2 ms 2260 KB correct
31 Correct 2 ms 2260 KB correct
32 Correct 2 ms 2260 KB correct
33 Correct 3 ms 2260 KB correct
34 Correct 73 ms 3536 KB correct
35 Correct 69 ms 3532 KB correct
36 Correct 59 ms 3284 KB correct
37 Correct 15 ms 2420 KB correct
38 Correct 72 ms 3536 KB correct
39 Correct 62 ms 3412 KB correct
40 Correct 59 ms 3260 KB correct
41 Correct 80 ms 3536 KB correct
42 Correct 71 ms 3536 KB correct
43 Correct 42 ms 3028 KB correct
44 Correct 37 ms 2896 KB correct
45 Correct 40 ms 2900 KB correct
46 Correct 38 ms 2760 KB correct
47 Correct 26 ms 2516 KB correct
48 Correct 8 ms 2260 KB correct
49 Correct 13 ms 2428 KB correct
50 Correct 22 ms 2596 KB correct
51 Correct 41 ms 2900 KB correct
52 Correct 37 ms 2900 KB correct
53 Correct 36 ms 2772 KB correct
54 Correct 47 ms 3020 KB correct
55 Correct 45 ms 2972 KB correct
56 Correct 42 ms 2900 KB correct
57 Correct 41 ms 2900 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2260 KB correct
2 Correct 1 ms 2260 KB correct
3 Correct 277 ms 5548 KB correct
4 Correct 507 ms 6484 KB correct
5 Correct 501 ms 6488 KB correct
6 Correct 507 ms 6500 KB correct
7 Correct 533 ms 7424 KB correct
8 Correct 518 ms 7488 KB correct
9 Correct 502 ms 7368 KB correct
10 Correct 518 ms 7424 KB correct
11 Correct 522 ms 7428 KB correct
12 Correct 509 ms 7440 KB correct
13 Correct 1 ms 2260 KB correct
14 Correct 514 ms 7420 KB correct
15 Correct 509 ms 7424 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2260 KB correct
2 Correct 1 ms 2260 KB correct
3 Correct 1 ms 2260 KB correct
4 Correct 1 ms 2260 KB correct
5 Correct 1 ms 2260 KB correct
6 Correct 1 ms 2260 KB correct
7 Correct 2 ms 2260 KB correct
8 Correct 2 ms 2260 KB correct
9 Correct 1 ms 2260 KB correct
10 Correct 1 ms 2260 KB correct
11 Correct 2 ms 2260 KB correct
12 Correct 1 ms 2260 KB correct
13 Correct 1 ms 2260 KB correct
14 Correct 4 ms 2296 KB correct
15 Correct 3 ms 2388 KB correct
16 Correct 3 ms 2388 KB correct
17 Correct 3 ms 2260 KB correct
18 Correct 2 ms 2260 KB correct
19 Correct 3 ms 2260 KB correct
20 Correct 3 ms 2260 KB correct
21 Correct 2 ms 2260 KB correct
22 Correct 2 ms 2260 KB correct
23 Correct 3 ms 2260 KB correct
24 Correct 2 ms 2260 KB correct
25 Correct 2 ms 2244 KB correct
26 Correct 3 ms 2260 KB correct
27 Correct 2 ms 2260 KB correct
28 Correct 2 ms 2244 KB correct
29 Correct 3 ms 2260 KB correct
30 Correct 2 ms 2260 KB correct
31 Correct 2 ms 2260 KB correct
32 Correct 2 ms 2260 KB correct
33 Correct 3 ms 2260 KB correct
34 Correct 73 ms 3536 KB correct
35 Correct 69 ms 3532 KB correct
36 Correct 59 ms 3284 KB correct
37 Correct 15 ms 2420 KB correct
38 Correct 72 ms 3536 KB correct
39 Correct 62 ms 3412 KB correct
40 Correct 59 ms 3260 KB correct
41 Correct 80 ms 3536 KB correct
42 Correct 71 ms 3536 KB correct
43 Correct 42 ms 3028 KB correct
44 Correct 37 ms 2896 KB correct
45 Correct 40 ms 2900 KB correct
46 Correct 38 ms 2760 KB correct
47 Correct 26 ms 2516 KB correct
48 Correct 8 ms 2260 KB correct
49 Correct 13 ms 2428 KB correct
50 Correct 22 ms 2596 KB correct
51 Correct 41 ms 2900 KB correct
52 Correct 37 ms 2900 KB correct
53 Correct 36 ms 2772 KB correct
54 Correct 47 ms 3020 KB correct
55 Correct 45 ms 2972 KB correct
56 Correct 42 ms 2900 KB correct
57 Correct 41 ms 2900 KB correct
58 Correct 1 ms 2260 KB correct
59 Correct 1 ms 2260 KB correct
60 Correct 277 ms 5548 KB correct
61 Correct 507 ms 6484 KB correct
62 Correct 501 ms 6488 KB correct
63 Correct 507 ms 6500 KB correct
64 Correct 533 ms 7424 KB correct
65 Correct 518 ms 7488 KB correct
66 Correct 502 ms 7368 KB correct
67 Correct 518 ms 7424 KB correct
68 Correct 522 ms 7428 KB correct
69 Correct 509 ms 7440 KB correct
70 Correct 1 ms 2260 KB correct
71 Correct 514 ms 7420 KB correct
72 Correct 509 ms 7424 KB correct
73 Correct 1 ms 2260 KB correct
74 Correct 520 ms 7420 KB correct
75 Correct 474 ms 7240 KB correct
76 Correct 190 ms 4244 KB correct
77 Correct 499 ms 7424 KB correct
78 Correct 529 ms 7400 KB correct
79 Correct 531 ms 7424 KB correct
80 Correct 494 ms 7288 KB correct
81 Correct 429 ms 6724 KB correct
82 Correct 503 ms 7308 KB correct
83 Correct 295 ms 5048 KB correct
84 Correct 324 ms 5872 KB correct
85 Correct 286 ms 5352 KB correct
86 Correct 232 ms 4372 KB correct
87 Correct 173 ms 3836 KB correct
88 Correct 160 ms 3392 KB correct
89 Correct 138 ms 3284 KB correct
90 Correct 123 ms 3296 KB correct
91 Correct 54 ms 2388 KB correct
92 Correct 35 ms 2388 KB correct
93 Correct 282 ms 5320 KB correct
94 Correct 224 ms 4432 KB correct
95 Correct 208 ms 4304 KB correct
96 Correct 131 ms 3284 KB correct
97 Correct 146 ms 3444 KB correct
98 Correct 177 ms 3792 KB correct
99 Correct 146 ms 3412 KB correct
100 Correct 72 ms 2644 KB correct
101 Correct 31 ms 2388 KB correct
102 Correct 302 ms 4936 KB correct
103 Correct 267 ms 4940 KB correct
104 Correct 274 ms 4812 KB correct
105 Correct 274 ms 4912 KB correct