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답안 #475493

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
475493 2021-09-22T17:43:30 Z blue Simurgh (IOI17_simurgh) C++17
100 / 100
 971 ms 18324 KB 
#include "simurgh.h"
#include <vector>
#include <iostream>
#include <set>
#include <algorithm>
using namespace std;

const int maxN = 500;
const int maxM = 500*499/2;

int N, M;

vector< vector<int> > edge_index(maxN, vector<int>(maxN, -1)); //index of edge in graph
vector<int> edge[maxN]; //list of edge destinations of each node in maain graph

vector<bool> edge_in_tree(maxM, 0); //is this edge index in the tree?

set<int> treeset; //set of edge indices in the basic spanning tree




vector<int> parent(maxN, -1); //parent of node in basic spanning tree
vector<int> depth(maxN, 0); //depth of node in basic spanning tree



const int unclear = -1;
const int good = 1;
const int bad = 0;

vector<bool> extra_visited(maxM, 0);

vector<int> state(maxM, unclear); //state of each edge.


void dfs(int u)
{
	// cerr << "u = " << u << '\n';
	for(int v: edge[u])
	{
		// cerr << u << " -> " << v << '\n';
		if(parent[u] == v || parent[v] != -1) continue;

		parent[v] = u;
		depth[v] = depth[u] + 1;

		edge_in_tree[ edge_index[u][v] ] = 1;
		treeset.insert(edge_index[u][v]);

		dfs(v);
	}
}

vector<int> findtree_ans(maxM, -1);

vector<int> get_vector(set<int> S)
{
	vector<int> K;
	for(int s:S) K.push_back(s);
	return K;
}





struct disjoint_set
{
	int N;
	vector<int> parent;
	vector<int> subtree;

	disjoint_set()
	{
		;
	}

	disjoint_set(int N_)
	{
		N = N_;
		parent = vector<int>(N);
		subtree = vector<int>(N, 1);
		for(int i = 0; i < N; i++) parent[i] = i;
	}

	int root(int u)
	{
		while(parent[u] != u) u = parent[u];
		return u;
	}

	bool connected(int u, int v)
	{
		return root(u) == root(v);
	}

	void join(int u, int v)
	{
		u = root(u);
		v = root(v);
		if(connected(u, v)) return;
		if(subtree[u] < subtree[v]) swap(u, v);
		parent[v] = u;
		subtree[u] += subtree[v];
	}
};







vector<int> find_roads(int n, vector<int> u, vector<int> v)
{
	cerr << "check zero\n";
//PART ONE
	N = n;
	M = (int)u.size();

	for(int j = 0; j < M; j++)
	{
		edge_index[ u[j] ][ v[j] ] = edge_index[ v[j] ][ u[j] ] = j;
		edge[ u[j] ].push_back( v[j] );
		edge[ v[j] ].push_back( u[j] );
	}
		// cerr << "check2\n";

	parent[0] = 0;
	dfs(0);
	// cerr << "check3\n";

	vector<int> Q;
	for(int j = 0; j < M; j++)
		if(edge_in_tree[j])
			Q.push_back(j);

	int basic_query = count_common_roads(Q);
	Q.clear();

	cerr << "check 1\n";

	// cerr << "check4\n";



	for(int j = 0; j < M; j++)
	{
		if(edge_in_tree[j]) continue;
			// cerr << "check5 " << j << '\n';

		vector<int> tree_path;
		int U = u[j], V = v[j];
		if(depth[U] > depth[V]) swap(U, V);
		// cerr << depth[V] - depth[U] << '\n';
		while(depth[V] != depth[U])
		{
			// cerr << "k = " << k << '\n';
			tree_path.push_back( edge_index[ V ][ parent[V] ] );
			V = parent[V];
		}
		// cerr << "check6 " << j << '\n';
		// cerr << U << ' ' << V << ' ' << depth[U] << ' ' << depth[V] << '\n';
		while(U != V)
		{
			tree_path.push_back( edge_index[U][ parent[U] ] );
			tree_path.push_back(edge_index[V][parent[V]]);
			U = parent[U];
			V = parent[V];
		}

		for(int t: tree_path)
			extra_visited[t] = 1;

		// cerr << "check7 " << j << '\n';

		vector<int> known;
		vector<int> unknown;
		int known_count = 0;
		for(int t: tree_path)
		{
			if(state[t] != unclear)
			{
				known.push_back(t);
				known_count++;
			}
			else
			{
				unknown.push_back(t);
			}
		}

		// cerr << "check8 " << j << '\n';

		if(known_count == (int)tree_path.size())
			continue;
		else if(known_count != 0)
		{
			treeset.insert(j);


			treeset.erase(known[0]);

			int this_basic = count_common_roads(get_vector(treeset));
			int cycle_weight = this_basic + state[known[0]];

			treeset.insert(known[0]);

			for(int u: unknown)
			{
				treeset.erase(u);
				state[u] = cycle_weight - count_common_roads(get_vector(treeset));
				treeset.insert(u);
			}

			treeset.erase(j);
		}
		else if(known_count == 0)
		{
			vector< pair<int, int> > cycle_elements;
			cycle_elements.push_back(make_pair(basic_query, j));
			for(int t: tree_path)
			{
				treeset.erase(t);
				treeset.insert(j);

				findtree_ans[t] = count_common_roads(get_vector(treeset));
				cycle_elements.push_back(make_pair(findtree_ans[t], t));

				treeset.erase(j);
				treeset.insert(t);
			}
			sort(cycle_elements.begin(), cycle_elements.end());

			bool good_flag = 0;

			for(int x = (int)cycle_elements.size() - 1; x >= 0; x--)
			{
				if(x < (int)cycle_elements.size() - 1 && cycle_elements[x].first != cycle_elements[x+1].first)
					good_flag = 1;

				if(good_flag)
					state[ cycle_elements[x].second ] = good;
				else
					state[ cycle_elements[x].second ] = bad;
			}
		}
		// cerr << "check9 " << j << '\n';
	}

	for(int e: treeset)
		if(extra_visited[e] == 0)
			state[e] = good;

	// cerr << "tree and states: \n";
	//
	// for(int j = 0; j < M; j++)
	// {
	// 	if(edge_in_tree[j])
	// 	{
	// 		cerr << u[j] << ' ' << v[j] << ' ' << state[j] << '\n';
	// 	}
	// }
	cerr << "check 2\n";












//PART TWO


	set<int> potential_new_neighbors[N];
	vector<int> new_neighbors_count(N, 0);
	for(int U = 0; U < N; U++)
	{
		for(int V = 0; V < N; V++)
		{
			if(U == V) continue;
			if(state[ edge_index[U][V] ] == unclear)
			{
				potential_new_neighbors[U].insert(V);
			}
		}
	}
	// cerr << "check 3\n";
	//
	// for(int t: treeset) cerr << t << ' ';
	// cerr << '\n';

	for(int U = 0; U < N; U++)
	{
		// cerr << "U = " << U << '\n';
		vector<int> query_vector;
		disjoint_set DSU(N);
		for(int V = 0; V < N; V++)
		{
			if(U == V) continue;

			if(edge_index[U][V] != -1)
			{
				if(state[ edge_index[U][V] ] == good)
					new_neighbors_count[U]--;

				DSU.join(U, V);
				query_vector.push_back(edge_index[U][V]);
			}
		}

		// cerr << "qv = ";
		// for(int qv: query_vector) cerr << qv << ' ';
		// cerr << '\n';
		//
		// for(int i = 0; i < N; i++)
		// 	cerr << DSU.root(i) << ' ';
		// cerr << '\n';

		for(int t: treeset)
		{
			// cerr << u[t] << ' ' << v[t] << ' ' << DSU.connected(u[t], v[t]) << '\n';
			if(!DSU.connected(u[t], v[t]))
			{
				// cerr << "joined!\n";
				DSU.join(u[t], v[t]);
				// cerr << u[t] << ' ' << v[t] << ' ' << DSU.connected(u[t], v[t]) << '\n';
				query_vector.push_back(t);
				if(state[t] == good)
					new_neighbors_count[U]--;

				// for(int i = 0; i < N; i++)
				// 	cerr << DSU.root(i) << ' ';
				// cerr << '\n';
			}
			// cerr << "\n";
		}
		// for(int i = 0; i < N; i++)
		// 	cerr << DSU.root(i) << ' ';
		// cerr << '\n';

		new_neighbors_count[U] += count_common_roads(query_vector);
	}
	cerr << "check 4\n";





	for(int Z = 1; Z <= N; Z++)
	{
		int U = -1;
		for(int y = 0; y < N; y++)
		{
			if(new_neighbors_count[y] == 1)
			{
				U = y;
				break;
			}
		}
		if(U == -1) break;

		vector<int> candidates;
		for(int V = 0; V < N; V++)
		{
			if(U == V) continue;
			if(edge_index[U][V] == -1) continue;

			if(state[ edge_index[U][V] ] == unclear)
				candidates.push_back(V);
		}

		int lo = 0;
		int hi = (int)candidates.size() - 1;
		while(lo != hi)
		{
			int mid = (lo+hi)/2;

			int prefix_candidates = 0;

			disjoint_set DSU(N);
			vector<int> query_vector;
			for(int i = 0; i <= mid; i++)
			{
				DSU.join(U, candidates[i]);
				query_vector.push_back(  edge_index[U][candidates[i]] );
			}

			for(int t: treeset)
			{
				if(DSU.connected(u[t], v[t])) continue;
				prefix_candidates -= state[ edge_index[u[t]][v[t]] ];
				DSU.join(u[t], v[t]);
				query_vector.push_back(t);
			}

			prefix_candidates += count_common_roads(query_vector);

			if(prefix_candidates >= 1) hi = mid;
			else lo = mid+1;
		}

		for(int c: candidates)
		{
			if(c == candidates[lo])
			{
				state[ edge_index[U][c] ] = good;
				new_neighbors_count[c]--;
			}
			else
			{
				state[ edge_index[U][c] ] = bad;
			}

			potential_new_neighbors[c].erase(U);
			potential_new_neighbors[U].erase(c);

			new_neighbors_count[U]--;
		}
	}
	cerr << "check 5\n";



	for(int j = 0; j < M; j++) cerr << state[j] << ' ';
	cerr << '\n';



	vector<int> res;
	for(int j = 0; j < M; j++)
		if(state[j] == good)
		{
			cerr << "adding " << j << '\n';
			res.push_back(j);
		}

	return res;
}

Subtask #1
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 2 ms 2324 KB correct
4 Correct 2 ms 2252 KB correct
5 Correct 2 ms 2252 KB correct
6 Correct 2 ms 2252 KB correct
7 Correct 2 ms 2252 KB correct
8 Correct 2 ms 2252 KB correct
9 Correct 2 ms 2252 KB correct
10 Correct 3 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 2 ms 2252 KB correct

Subtask #2
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 2 ms 2324 KB correct
4 Correct 2 ms 2252 KB correct
5 Correct 2 ms 2252 KB correct
6 Correct 2 ms 2252 KB correct
7 Correct 2 ms 2252 KB correct
8 Correct 2 ms 2252 KB correct
9 Correct 2 ms 2252 KB correct
10 Correct 3 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 2 ms 2252 KB correct
14 Correct 10 ms 2380 KB correct
15 Correct 8 ms 2380 KB correct
16 Correct 7 ms 2432 KB correct
17 Correct 7 ms 2460 KB correct
18 Correct 4 ms 2252 KB correct
19 Correct 7 ms 2380 KB correct
20 Correct 7 ms 2456 KB correct
21 Correct 7 ms 2380 KB correct
22 Correct 5 ms 2428 KB correct
23 Correct 5 ms 2380 KB correct
24 Correct 4 ms 2380 KB correct
25 Correct 3 ms 2252 KB correct
26 Correct 4 ms 2380 KB correct
27 Correct 5 ms 2380 KB correct
28 Correct 3 ms 2324 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 6 ms 2380 KB correct
31 Correct 5 ms 2332 KB correct
32 Correct 5 ms 2380 KB correct
33 Correct 5 ms 2412 KB correct

Subtask #3
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 2 ms 2324 KB correct
4 Correct 2 ms 2252 KB correct
5 Correct 2 ms 2252 KB correct
6 Correct 2 ms 2252 KB correct
7 Correct 2 ms 2252 KB correct
8 Correct 2 ms 2252 KB correct
9 Correct 2 ms 2252 KB correct
10 Correct 3 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 2 ms 2252 KB correct
14 Correct 10 ms 2380 KB correct
15 Correct 8 ms 2380 KB correct
16 Correct 7 ms 2432 KB correct
17 Correct 7 ms 2460 KB correct
18 Correct 4 ms 2252 KB correct
19 Correct 7 ms 2380 KB correct
20 Correct 7 ms 2456 KB correct
21 Correct 7 ms 2380 KB correct
22 Correct 5 ms 2428 KB correct
23 Correct 5 ms 2380 KB correct
24 Correct 4 ms 2380 KB correct
25 Correct 3 ms 2252 KB correct
26 Correct 4 ms 2380 KB correct
27 Correct 5 ms 2380 KB correct
28 Correct 3 ms 2324 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 6 ms 2380 KB correct
31 Correct 5 ms 2332 KB correct
32 Correct 5 ms 2380 KB correct
33 Correct 5 ms 2412 KB correct
34 Correct 169 ms 5932 KB correct
35 Correct 180 ms 5856 KB correct
36 Correct 127 ms 4732 KB correct
37 Correct 21 ms 2464 KB correct
38 Correct 166 ms 5968 KB correct
39 Correct 152 ms 5360 KB correct
40 Correct 120 ms 4728 KB correct
41 Correct 171 ms 5980 KB correct
42 Correct 166 ms 5956 KB correct
43 Correct 99 ms 4320 KB correct
44 Correct 69 ms 3788 KB correct
45 Correct 82 ms 4132 KB correct
46 Correct 68 ms 3684 KB correct
47 Correct 34 ms 2944 KB correct
48 Correct 10 ms 2368 KB correct
49 Correct 20 ms 2500 KB correct
50 Correct 38 ms 2940 KB correct
51 Correct 101 ms 4112 KB correct
52 Correct 68 ms 3888 KB correct
53 Correct 62 ms 3700 KB correct
54 Correct 83 ms 4332 KB correct
55 Correct 88 ms 4112 KB correct
56 Correct 82 ms 4108 KB correct
57 Correct 85 ms 4120 KB correct

Subtask #4
19.0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 585 ms 12640 KB correct
4 Correct 920 ms 18184 KB correct
5 Correct 923 ms 18244 KB correct
6 Correct 925 ms 18128 KB correct
7 Correct 925 ms 18212 KB correct
8 Correct 908 ms 18260 KB correct
9 Correct 909 ms 18196 KB correct
10 Correct 953 ms 18168 KB correct
11 Correct 971 ms 18188 KB correct
12 Correct 957 ms 18204 KB correct
13 Correct 2 ms 2252 KB correct
14 Correct 967 ms 18256 KB correct
15 Correct 971 ms 18200 KB correct

Subtask #5
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 2 ms 2324 KB correct
4 Correct 2 ms 2252 KB correct
5 Correct 2 ms 2252 KB correct
6 Correct 2 ms 2252 KB correct
7 Correct 2 ms 2252 KB correct
8 Correct 2 ms 2252 KB correct
9 Correct 2 ms 2252 KB correct
10 Correct 3 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 2 ms 2252 KB correct
14 Correct 10 ms 2380 KB correct
15 Correct 8 ms 2380 KB correct
16 Correct 7 ms 2432 KB correct
17 Correct 7 ms 2460 KB correct
18 Correct 4 ms 2252 KB correct
19 Correct 7 ms 2380 KB correct
20 Correct 7 ms 2456 KB correct
21 Correct 7 ms 2380 KB correct
22 Correct 5 ms 2428 KB correct
23 Correct 5 ms 2380 KB correct
24 Correct 4 ms 2380 KB correct
25 Correct 3 ms 2252 KB correct
26 Correct 4 ms 2380 KB correct
27 Correct 5 ms 2380 KB correct
28 Correct 3 ms 2324 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 6 ms 2380 KB correct
31 Correct 5 ms 2332 KB correct
32 Correct 5 ms 2380 KB correct
33 Correct 5 ms 2412 KB correct
34 Correct 169 ms 5932 KB correct
35 Correct 180 ms 5856 KB correct
36 Correct 127 ms 4732 KB correct
37 Correct 21 ms 2464 KB correct
38 Correct 166 ms 5968 KB correct
39 Correct 152 ms 5360 KB correct
40 Correct 120 ms 4728 KB correct
41 Correct 171 ms 5980 KB correct
42 Correct 166 ms 5956 KB correct
43 Correct 99 ms 4320 KB correct
44 Correct 69 ms 3788 KB correct
45 Correct 82 ms 4132 KB correct
46 Correct 68 ms 3684 KB correct
47 Correct 34 ms 2944 KB correct
48 Correct 10 ms 2368 KB correct
49 Correct 20 ms 2500 KB correct
50 Correct 38 ms 2940 KB correct
51 Correct 101 ms 4112 KB correct
52 Correct 68 ms 3888 KB correct
53 Correct 62 ms 3700 KB correct
54 Correct 83 ms 4332 KB correct
55 Correct 88 ms 4112 KB correct
56 Correct 82 ms 4108 KB correct
57 Correct 85 ms 4120 KB correct
58 Correct 1 ms 2252 KB correct
59 Correct 2 ms 2252 KB correct
60 Correct 585 ms 12640 KB correct
61 Correct 920 ms 18184 KB correct
62 Correct 923 ms 18244 KB correct
63 Correct 925 ms 18128 KB correct
64 Correct 925 ms 18212 KB correct
65 Correct 908 ms 18260 KB correct
66 Correct 909 ms 18196 KB correct
67 Correct 953 ms 18168 KB correct
68 Correct 971 ms 18188 KB correct
69 Correct 957 ms 18204 KB correct
70 Correct 2 ms 2252 KB correct
71 Correct 967 ms 18256 KB correct
72 Correct 971 ms 18200 KB correct
73 Correct 2 ms 2252 KB correct
74 Correct 938 ms 18280 KB correct
75 Correct 886 ms 17692 KB correct
76 Correct 368 ms 8000 KB correct
77 Correct 951 ms 18324 KB correct
78 Correct 932 ms 18224 KB correct
79 Correct 952 ms 18172 KB correct
80 Correct 902 ms 17756 KB correct
81 Correct 768 ms 15520 KB correct
82 Correct 967 ms 17740 KB correct
83 Correct 523 ms 10320 KB correct
84 Correct 487 ms 11852 KB correct
85 Correct 415 ms 10896 KB correct
86 Correct 300 ms 8316 KB correct
87 Correct 214 ms 6616 KB correct
88 Correct 173 ms 5444 KB correct
89 Correct 170 ms 5248 KB correct
90 Correct 178 ms 4836 KB correct
91 Correct 55 ms 2608 KB correct
92 Correct 39 ms 2432 KB correct
93 Correct 454 ms 10828 KB correct
94 Correct 279 ms 8132 KB correct
95 Correct 277 ms 7976 KB correct
96 Correct 159 ms 5020 KB correct
97 Correct 184 ms 5552 KB correct
98 Correct 208 ms 6504 KB correct
99 Correct 187 ms 5656 KB correct
100 Correct 79 ms 3008 KB correct
101 Correct 40 ms 2456 KB correct
102 Correct 493 ms 10360 KB correct
103 Correct 490 ms 10352 KB correct
104 Correct 446 ms 10248 KB correct
105 Correct 448 ms 10280 KB correct