| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 832075 |
2023-08-20T22:00:21 Z |
finn__ |
Simurgh (IOI17_simurgh) |
C++17 |
|
1 ms |
468 KB |
#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;
namespace quadratic
{
constexpr size_t N = 240;
vector<pair<int, int>> g[N];
int adj[N][N];
bitset<N *(N - 1) / 2> checked, is_in;
vector<int> solve(int n, vector<int> u, vector<int> v)
{
memset(adj, 255, sizeof adj);
for (int i = 0; i < u.size(); ++i)
g[u[i]].emplace_back(v[i], i), g[v[i]].emplace_back(u[i], i), adj[u[i]][v[i]] = adj[v[i]][u[i]] = i;
vector<int> ans;
for (int i = 0; i < n; ++i)
{
vector<vector<int>> bccs, bcc_trees;
vector<int> edge_to_bcc;
bitset<N> visited;
visited[i] = 1;
for (auto const &[z, j] : g[i])
if (!visited[z])
{
queue<int> q({z});
visited[z] = 1;
edge_to_bcc.push_back(j);
vector<int> nodes, edges;
while (!q.empty())
{
int x = q.front();
nodes.push_back(x);
q.pop();
for (auto const &[y, i] : g[x])
if (!visited[y])
{
edges.push_back(i);
q.push(y);
visited[y] = 1;
}
}
bccs.push_back(nodes);
bcc_trees.push_back(edges);
}
for (size_t j = 0; j < bccs.size(); ++j)
{
vector<int> spanning_tree;
for (size_t k = 0; k < bccs.size(); ++k)
{
spanning_tree.insert(spanning_tree.end(), bcc_trees[k].begin(), bcc_trees[k].end());
if (k != j)
spanning_tree.push_back(edge_to_bcc[k]);
}
for (auto const &x : bccs[j])
if (adj[i][x] != -1)
{
spanning_tree.push_back(adj[i][x]);
break;
}
int in_overlap = count_common_roads(spanning_tree), out_overlap = in_overlap;
vector<int> in;
bool skipped = 0, know_in = 0;
for (auto const &x : bccs[j])
if (adj[i][x] != -1)
{
if (!skipped)
{
checked[adj[i][x]] = 1;
in.push_back(adj[i][x]);
skipped = 1;
continue;
}
if (checked[adj[i][x]] && know_in)
continue;
spanning_tree.pop_back();
spanning_tree.push_back(adj[i][x]);
int y = count_common_roads(spanning_tree);
if (!know_in)
{
if (checked[adj[i][x]])
{
know_in = 1;
if (is_in[adj[i][x]])
{
if (in_overlap < y)
in.clear(), ++in_overlap;
else
--out_overlap;
}
else
{
if (in_overlap == y)
in.clear(), ++in_overlap;
else
--out_overlap;
}
}
if (y == in_overlap)
in.push_back(adj[i][x]);
else if (y < in_overlap)
{
out_overlap--;
know_in = 1;
}
else if (y > in_overlap)
{
know_in = 1;
in.clear();
in_overlap++;
in.push_back(adj[i][x]);
}
}
else if (y == in_overlap)
in.push_back(adj[i][x]);
checked[adj[i][x]] = 1;
}
ans.insert(ans.end(), in.begin(), in.end());
for (auto const &j : in)
is_in[j] = 1;
}
}
sort(ans.begin(), ans.end());
ans.resize(unique(ans.begin(), ans.end()) - ans.begin());
return ans;
}
};
template <size_t N>
struct dsu
{
int p[N];
int repr(int u) { return p[u] < 0 ? u : p[u] = repr(p[u]); }
bool merge(int u, int v)
{
u = repr(u), v = repr(v);
if (u == v)
return 0;
if (p[u] > p[v])
swap(u, v);
p[u] += p[v];
p[v] = u;
return 1;
}
int set_size(int u) { return -p[repr(u)]; }
void reset() { memset(p, 255, sizeof p); }
};
namespace nlogn
{
constexpr size_t N = 500;
int adj[N][N], degree[N];
bitset<N *(N - 1) / 2> is_in, removed;
dsu<N> d;
vector<int> solve(int n, vector<int> u, vector<int> v)
{
for (int i = 0; i < u.size(); ++i)
adj[u[i]][v[i]] = adj[v[i]][u[i]] = i;
auto query_forest = [&](vector<int> forest)
{
d.reset();
for (int i : forest)
d.merge(u[i], v[i]);
int ans = 0;
for (int i = 0; i + 1 < n; ++i)
if (d.merge(i, i + 1))
{
if (is_in[adj[i][i + 1]])
--ans;
forest.push_back(adj[i][i + 1]);
}
return ans + count_common_roads(forest);
};
auto check_edge = [&](int u, int v)
{
int w = 0;
while (w == u || w == v)
++w;
vector<int> spanning_tree;
for (int i = 0; i < n; ++i)
if (i != u && i != v && i != w)
spanning_tree.push_back(adj[u][i]);
spanning_tree.push_back(adj[u][v]);
spanning_tree.push_back(adj[v][w]);
int a = count_common_roads(spanning_tree);
spanning_tree[spanning_tree.size() - 2] = adj[w][u];
int b = count_common_roads(spanning_tree);
spanning_tree[spanning_tree.size() - 1] = adj[u][v];
int c = count_common_roads(spanning_tree);
return max(a, c) > b;
};
for (int i = 0; i + 1 < n; ++i)
is_in[adj[i][i + 1]] = check_edge(i, i + 1);
for (int i = 0; i < n; ++i)
{
vector<int> spanning_tree;
for (int j = 0; j < n; ++j)
if (i != j)
spanning_tree.push_back(adj[i][j]);
degree[i] = count_common_roads(spanning_tree);
}
queue<int> q;
for (int i = 0; i < n; ++i)
if (degree[i] == 1)
q.push(i);
vector<int> ans;
while (ans.size() != n - 1)
{
int x = q.front();
q.pop();
int a = 0, b = n - 1;
while (a < b)
{
int mid = (a + b) / 2;
vector<int> forest;
for (int j = 0; j <= mid; ++j)
if (j != x && !removed[adj[x][j]])
forest.push_back(adj[x][j]);
if (query_forest(forest))
b = mid;
else
a = mid + 1;
}
removed[adj[x][a]] = 1;
ans.push_back(adj[a][x]);
degree[a]--;
if (degree[a] == 1)
q.push(a);
}
return ans;
}
};
vector<int> find_roads(int n, vector<int> u, vector<int> v)
{
if (u.size() != n * (n - 1) / 2)
return quadratic::solve(n, u, v);
else
return nlogn::solve(n, u, v);
}
Compilation message
simurgh.cpp: In function 'std::vector<int> quadratic::solve(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:16:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
16 | for (int i = 0; i < u.size(); ++i)
| ~~^~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> nlogn::solve(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:177:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
177 | for (int i = 0; i < u.size(); ++i)
| ~~^~~~~~~~~~
simurgh.cpp:233:27: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
233 | while (ans.size() != n - 1)
| ~~~~~~~~~~~^~~~~~~~
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:266:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
266 | if (u.size() != n * (n - 1) / 2)
| ~~~~~~~~~^~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
correct |
| 2 |
Correct |
0 ms |
212 KB |
correct |
| 3 |
Correct |
0 ms |
212 KB |
correct |
| 4 |
Correct |
1 ms |
468 KB |
correct |
| 5 |
Correct |
0 ms |
468 KB |
correct |
| 6 |
Correct |
0 ms |
468 KB |
correct |
| 7 |
Incorrect |
1 ms |
212 KB |
WA in grader: NO |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
correct |
| 2 |
Correct |
0 ms |
212 KB |
correct |
| 3 |
Correct |
0 ms |
212 KB |
correct |
| 4 |
Correct |
1 ms |
468 KB |
correct |
| 5 |
Correct |
0 ms |
468 KB |
correct |
| 6 |
Correct |
0 ms |
468 KB |
correct |
| 7 |
Incorrect |
1 ms |
212 KB |
WA in grader: NO |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
correct |
| 2 |
Correct |
0 ms |
212 KB |
correct |
| 3 |
Correct |
0 ms |
212 KB |
correct |
| 4 |
Correct |
1 ms |
468 KB |
correct |
| 5 |
Correct |
0 ms |
468 KB |
correct |
| 6 |
Correct |
0 ms |
468 KB |
correct |
| 7 |
Incorrect |
1 ms |
212 KB |
WA in grader: NO |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
WA in grader: NO |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
correct |
| 2 |
Correct |
0 ms |
212 KB |
correct |
| 3 |
Correct |
0 ms |
212 KB |
correct |
| 4 |
Correct |
1 ms |
468 KB |
correct |
| 5 |
Correct |
0 ms |
468 KB |
correct |
| 6 |
Correct |
0 ms |
468 KB |
correct |
| 7 |
Incorrect |
1 ms |
212 KB |
WA in grader: NO |
| 8 |
Halted |
0 ms |
0 KB |
- |
