oj.uz

Submission #475494

# Submission time Handle Problem Language Result Execution time Memory
475494 2021-09-22T17:44:12 Z blue Simurgh (IOI17_simurgh) C++17
100 / 100
 692 ms 17212 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

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 1 ms 2252 KB correct
3 Correct 2 ms 2252 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 1 ms 2252 KB correct
8 Correct 1 ms 2252 KB correct
9 Correct 1 ms 2252 KB correct
10 Correct 2 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 1 ms 2252 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 1 ms 2252 KB correct
3 Correct 2 ms 2252 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 1 ms 2252 KB correct
8 Correct 1 ms 2252 KB correct
9 Correct 1 ms 2252 KB correct
10 Correct 2 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 1 ms 2252 KB correct
14 Correct 4 ms 2380 KB correct
15 Correct 4 ms 2380 KB correct
16 Correct 4 ms 2380 KB correct
17 Correct 4 ms 2444 KB correct
18 Correct 3 ms 2252 KB correct
19 Correct 4 ms 2380 KB correct
20 Correct 4 ms 2380 KB correct
21 Correct 4 ms 2380 KB correct
22 Correct 3 ms 2380 KB correct
23 Correct 3 ms 2380 KB correct
24 Correct 3 ms 2380 KB correct
25 Correct 2 ms 2252 KB correct
26 Correct 3 ms 2380 KB correct
27 Correct 3 ms 2380 KB correct
28 Correct 3 ms 2252 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 3 ms 2348 KB correct
31 Correct 3 ms 2380 KB correct
32 Correct 3 ms 2380 KB correct
33 Correct 3 ms 2380 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 1 ms 2252 KB correct
3 Correct 2 ms 2252 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 1 ms 2252 KB correct
8 Correct 1 ms 2252 KB correct
9 Correct 1 ms 2252 KB correct
10 Correct 2 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 1 ms 2252 KB correct
14 Correct 4 ms 2380 KB correct
15 Correct 4 ms 2380 KB correct
16 Correct 4 ms 2380 KB correct
17 Correct 4 ms 2444 KB correct
18 Correct 3 ms 2252 KB correct
19 Correct 4 ms 2380 KB correct
20 Correct 4 ms 2380 KB correct
21 Correct 4 ms 2380 KB correct
22 Correct 3 ms 2380 KB correct
23 Correct 3 ms 2380 KB correct
24 Correct 3 ms 2380 KB correct
25 Correct 2 ms 2252 KB correct
26 Correct 3 ms 2380 KB correct
27 Correct 3 ms 2380 KB correct
28 Correct 3 ms 2252 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 3 ms 2348 KB correct
31 Correct 3 ms 2380 KB correct
32 Correct 3 ms 2380 KB correct
33 Correct 3 ms 2380 KB correct
34 Correct 89 ms 5624 KB correct
35 Correct 88 ms 5504 KB correct
36 Correct 70 ms 4604 KB correct
37 Correct 18 ms 2488 KB correct
38 Correct 103 ms 5768 KB correct
39 Correct 110 ms 5188 KB correct
40 Correct 83 ms 4548 KB correct
41 Correct 90 ms 5700 KB correct
42 Correct 88 ms 5620 KB correct
43 Correct 43 ms 4292 KB correct
44 Correct 38 ms 3776 KB correct
45 Correct 40 ms 4000 KB correct
46 Correct 33 ms 3556 KB correct
47 Correct 21 ms 2916 KB correct
48 Correct 9 ms 2376 KB correct
49 Correct 13 ms 2496 KB correct
50 Correct 21 ms 2908 KB correct
51 Correct 40 ms 3992 KB correct
52 Correct 32 ms 3788 KB correct
53 Correct 32 ms 3552 KB correct
54 Correct 42 ms 4172 KB correct
55 Correct 45 ms 4008 KB correct
56 Correct 58 ms 3988 KB correct
57 Correct 45 ms 3968 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 2 ms 2252 KB correct
3 Correct 336 ms 12032 KB correct
4 Correct 586 ms 17060 KB correct
5 Correct 637 ms 17060 KB correct
6 Correct 622 ms 17060 KB correct
7 Correct 692 ms 17056 KB correct
8 Correct 586 ms 17068 KB correct
9 Correct 588 ms 17008 KB correct
10 Correct 665 ms 17176 KB correct
11 Correct 611 ms 16996 KB correct
12 Correct 625 ms 17212 KB correct
13 Correct 2 ms 2252 KB correct
14 Correct 617 ms 17172 KB correct
15 Correct 634 ms 17064 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2252 KB correct
2 Correct 1 ms 2252 KB correct
3 Correct 2 ms 2252 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 1 ms 2252 KB correct
8 Correct 1 ms 2252 KB correct
9 Correct 1 ms 2252 KB correct
10 Correct 2 ms 2252 KB correct
11 Correct 2 ms 2252 KB correct
12 Correct 2 ms 2252 KB correct
13 Correct 1 ms 2252 KB correct
14 Correct 4 ms 2380 KB correct
15 Correct 4 ms 2380 KB correct
16 Correct 4 ms 2380 KB correct
17 Correct 4 ms 2444 KB correct
18 Correct 3 ms 2252 KB correct
19 Correct 4 ms 2380 KB correct
20 Correct 4 ms 2380 KB correct
21 Correct 4 ms 2380 KB correct
22 Correct 3 ms 2380 KB correct
23 Correct 3 ms 2380 KB correct
24 Correct 3 ms 2380 KB correct
25 Correct 2 ms 2252 KB correct
26 Correct 3 ms 2380 KB correct
27 Correct 3 ms 2380 KB correct
28 Correct 3 ms 2252 KB correct
29 Correct 3 ms 2252 KB correct
30 Correct 3 ms 2348 KB correct
31 Correct 3 ms 2380 KB correct
32 Correct 3 ms 2380 KB correct
33 Correct 3 ms 2380 KB correct
34 Correct 89 ms 5624 KB correct
35 Correct 88 ms 5504 KB correct
36 Correct 70 ms 4604 KB correct
37 Correct 18 ms 2488 KB correct
38 Correct 103 ms 5768 KB correct
39 Correct 110 ms 5188 KB correct
40 Correct 83 ms 4548 KB correct
41 Correct 90 ms 5700 KB correct
42 Correct 88 ms 5620 KB correct
43 Correct 43 ms 4292 KB correct
44 Correct 38 ms 3776 KB correct
45 Correct 40 ms 4000 KB correct
46 Correct 33 ms 3556 KB correct
47 Correct 21 ms 2916 KB correct
48 Correct 9 ms 2376 KB correct
49 Correct 13 ms 2496 KB correct
50 Correct 21 ms 2908 KB correct
51 Correct 40 ms 3992 KB correct
52 Correct 32 ms 3788 KB correct
53 Correct 32 ms 3552 KB correct
54 Correct 42 ms 4172 KB correct
55 Correct 45 ms 4008 KB correct
56 Correct 58 ms 3988 KB correct
57 Correct 45 ms 3968 KB correct
58 Correct 2 ms 2252 KB correct
59 Correct 2 ms 2252 KB correct
60 Correct 336 ms 12032 KB correct
61 Correct 586 ms 17060 KB correct
62 Correct 637 ms 17060 KB correct
63 Correct 622 ms 17060 KB correct
64 Correct 692 ms 17056 KB correct
65 Correct 586 ms 17068 KB correct
66 Correct 588 ms 17008 KB correct
67 Correct 665 ms 17176 KB correct
68 Correct 611 ms 16996 KB correct
69 Correct 625 ms 17212 KB correct
70 Correct 2 ms 2252 KB correct
71 Correct 617 ms 17172 KB correct
72 Correct 634 ms 17064 KB correct
73 Correct 2 ms 2252 KB correct
74 Correct 617 ms 17072 KB correct
75 Correct 573 ms 16700 KB correct
76 Correct 232 ms 7620 KB correct
77 Correct 604 ms 17056 KB correct
78 Correct 658 ms 17132 KB correct
79 Correct 606 ms 17124 KB correct
80 Correct 631 ms 16616 KB correct
81 Correct 515 ms 14612 KB correct
82 Correct 608 ms 16452 KB correct
83 Correct 394 ms 9840 KB correct
84 Correct 267 ms 11052 KB correct
85 Correct 266 ms 10252 KB correct
86 Correct 174 ms 7692 KB correct
87 Correct 132 ms 6084 KB correct
88 Correct 112 ms 5356 KB correct
89 Correct 111 ms 5072 KB correct
90 Correct 101 ms 4676 KB correct
91 Correct 45 ms 2604 KB correct
92 Correct 31 ms 2408 KB correct
93 Correct 230 ms 10224 KB correct
94 Correct 165 ms 7656 KB correct
95 Correct 159 ms 7452 KB correct
96 Correct 106 ms 4804 KB correct
97 Correct 118 ms 5224 KB correct
98 Correct 127 ms 6212 KB correct
99 Correct 114 ms 5352 KB correct
100 Correct 65 ms 2956 KB correct
101 Correct 44 ms 2444 KB correct
102 Correct 292 ms 9756 KB correct
103 Correct 301 ms 9712 KB correct
104 Correct 275 ms 9700 KB correct
105 Correct 275 ms 9720 KB correct