#include <bits/stdc++.h>
using namespace std;
#define int long long
int N, M;
map<int, vector<int>> conn;
int make_subtree(int n, map<int, vector<int>>& tree, bool only_path) {
int dep = 1;
for (int i : conn[n]) {
if (tree.find(i) == tree.end() && none_of(tree[n].begin(), tree[n].end(), [&](int j){ return find(conn[i].begin(), conn[i].end(), j) != conn[i].end(); })) {
tree[n].push_back(i);
tree[i] = {};
dep = max(dep, make_subtree(i, tree, only_path) + 1);
if (only_path) break;
}
}
return dep;
}
tuple<int, int, map<int, vector<int>>, int, int> make_tree() {
pair<int, int> best_dep = {N+1, N+1};
tuple<int, int, map<int, vector<int>>, int, int> best_tree;
for (int root = 0; root < N; ++root) {
for (int subroot : conn[root]) {
map<int, vector<int>> tree;
tree[root] = {subroot};
tree[subroot] = {};
int tree_dep = make_subtree(root, tree, false);
int path_dep = make_subtree(subroot, tree, true);
if (tree.size() == N && make_pair(path_dep, tree_dep) < best_dep) {
best_dep = {path_dep, tree_dep};
best_tree = {root, subroot, tree, tree_dep, path_dep};
}
}
}
return best_tree;
}
vector<int> get_path(int n, map<int, vector<int>>& tree, int skip) {
for (int i : tree[n]) {
if (i != skip) {
vector<int> result = get_path(i, tree, -1);
result.insert(result.begin(), n);
return result;
}
}
return {n};
}
set<int> get_next(int n, vector<int>& move) {
set<int> res;
for (int i : conn[n]) {
if (move[i] == move[n]) res.insert(i);
}
if (res.empty()) res.insert(n);
return res;
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
cin >> N >> M;
for (int i = 0; i < M; ++i) {
int a, b;
cin >> a >> b;
conn[a].push_back(b);
conn[b].push_back(a);
}
auto [root, subroot, tree, tree_dep, path_dep] = make_tree();
vector<int> even(N), odd(N), path;
vector<vector<int>> base_moves;
if (tree_dep + path_dep == N) {
vector<int> p1 = get_path(subroot, tree, -1);
vector<int> p2 = get_path(root, tree, subroot);
reverse(p1.begin(), p1.end());
path = p1;
path.insert(path.end(), p2.begin(), p2.end());
for (int i = 0; i < N / 2; ++i) {
even[path[2 * i]] = even[path[2 * i + 1]];
if (2 * i + 2 < N)
odd[path[2 * i + 1]] = even[path[2 * i + 2]];
}
base_moves = {even, odd};
} else {
even = vector<int>(N);
odd = vector<int>(N);
function<void(int, int)> gen_moves = [&](int n, int depth) {
if (depth % 2 == 0) even[n] = n;
else odd[n] = n;
for (int i : tree[n]) {
if (depth % 2 == 0) even[i] = n;
else odd[i] = n;
gen_moves(i, depth + 1);
}
};
gen_moves(root, 0);
gen_moves(subroot, 0);
odd[subroot] = root;
even[subroot] = subroot;
function<pair<int, int>(int, int)> end_of_path = [&](int n, int par) {
for (int i : tree[n]) return end_of_path(i, n);
return make_pair(n, par);
};
auto [end1, end2] = end_of_path(subroot, root);
odd[end1] = end2;
even[end1] = end2;
base_moves = {even, odd};
}
set<pair<int, int>> pos;
for (int a = 0; a < N; ++a)
for (int b = 0; b < a; ++b)
pos.insert({a, b});
vector<vector<int>> moves;
while (!pos.empty()) {
vector<int> move = base_moves[moves.size() % base_moves.size()];
moves.push_back(move);
set<pair<int, int>> npos;
for (auto [a, b] : pos) {
set<int> na = get_next(a, move), nb = get_next(b, move);
for (int aa : na)
for (int bb : nb)
if (aa != bb && !(aa == b && bb == a))
npos.insert({aa, bb});
}
pos = npos;
}
cout << moves.size() << '\n';
for (const auto& move : moves) {
for (int i : move) cout << i << ' ';
cout << '\n';
}
}
Compilation message
Main.cpp: In function 'std::tuple<long long int, long long int, std::map<long long int, std::vector<long long int, std::allocator<long long int> >, std::less<long long int>, std::allocator<std::pair<const long long int, std::vector<long long int, std::allocator<long long int> > > > >, long long int, long long int> make_tree()':
Main.cpp:31:29: warning: comparison of integer expressions of different signedness: 'std::map<long long int, std::vector<long long int> >::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
31 | if (tree.size() == N && make_pair(path_dep, tree_dep) < best_dep) {
| ~~~~~~~~~~~~^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Runtime error |
4370 ms |
1048576 KB |
Execution killed with signal 9 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Execution timed out |
9104 ms |
656884 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Runtime error |
4371 ms |
1048576 KB |
Execution killed with signal 9 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Runtime error |
4370 ms |
1048576 KB |
Execution killed with signal 9 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Runtime error |
4370 ms |
1048576 KB |
Execution killed with signal 9 |
| 3 |
Halted |
0 ms |
0 KB |
- |
