#if defined(ONPC) && !defined(_GLIBCXX_ASSERTIONS)
#define _GLIBCXX_ASSERTIONS
#endif
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#ifdef ONPC
#include "t_debug.cpp"
#else
#endif
#define debug(...) 42
#define allit(a) (a).begin(), (a).end()
#define sz(a) ((int) (a).size())
using namespace std;
using ll = long long;
using vi = vector<int>;
namespace pd = __gnu_pbds;
template<typename K>
using ordered_set = pd::tree<K, pd::null_type, less<int>, pd::rb_tree_tag, pd::tree_order_statistics_node_update>;
template<typename... T>
using gp_hash_table = pd::gp_hash_table<T...>;//simple using statement gives warnings
const int INF = 1e9;
const ll INFL = 1e18;
const int N = 1e5;
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937 rng(RANDOM);
int ans;
void confirm(int i) {
#ifdef ONPC
if (i == ans) cout << "ok " << i << endl;
else cout << "wrong " << i << ", expected " << ans << endl;
#else
cout << i << '\n';
#endif
}
int solve() {
int n; cin >> n;
map<string, int> code;
vector<string> name(n);
vi adj(n);
vector<set<int>> rev(n);
for (int i = 0, t = 0; i < n; i++) {
string u, v;
cin >> u >> v;
if (code.count(u) == 0) {
name[t] = u;
code[u] = t++;
}
if (code.count(v) == 0) {
name[t] = v;
code[v] = t++;
}
adj[code[u]] = code[v];
rev[code[v]].insert(code[u]);
}
if (n % 2 == 1) {confirm(-1); return 0;}
vi inrel(n);
int inrel_count = 0;
for (int i = 0; i <n; i++) {
inrel_count += inrel[i] = (
i != adj[i] && adj[adj[i]] == i);
}
debug(name);
debug(adj, rev, inrel);
int res = 0;
//unloved ones shall be matched
{
set<int> unloved;
for (int i = 0; i < n; i++) {
if (rev[i].empty()) {
if (inrel[adj[i]]) adj[i] = i;
else unloved.insert(i);
}
}
function<void()> action = [&]() {
while (!unloved.empty()) {
int i = *unloved.begin();
unloved.erase(unloved.begin());
if (rev[i].empty() && !inrel[adj[i]]) {
int a1 = i, a2 = adj[i];
assert(!inrel[a1]);
rev[adj[a2]].erase(a2);
if (rev[i].empty()) {
if (inrel[adj[i]]) adj[i] = i;
else unloved.insert(i);
}
for (int i : rev[a2]) {
adj[i] = i;
rev[i].insert(i);
}
rev[a1] = {a2};
adj[a2] = a1;
adj[a1] = a2;
inrel[a1] = inrel[a2] = 1;
inrel_count+= 2;
res++;
//debug(i, adj, rev, inrel);
}
}
};
action();
vi adj_p = adj;
action();
assert(adj == adj_p);
}
debug(res);
// polygons shall no longer survive
if (inrel_count != n) {
vi visited(n, 0);
auto cycle = [&](int i, int depth) {
res += (depth + 1) / 2;
debug("cycle", i, depth);
};
function<pair<int,int>(int)> dfs = [&](int i) -> pair<int,int> {
if (inrel[i]) return {-1, -1};
if (visited[i]) { return {i, 0}; }
debug("dfs", i);
visited[i] = 1;
auto [end, depth] = dfs(adj[i]);
if (end == -1) return {-1, -1};
depth++;
inrel[i] = 1;
if (end == i) {
cycle(end, depth);
assert(depth != 2);
return {-1, -1};
}
return {end, depth};
};
for (int i = 0; i < n; i++) {
if (!inrel[i] && !visited[i]) {
auto [end, depth] = dfs(i);
if (end != -1) cycle(end, depth);
}
}
}
confirm(res);
return 0;
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
int t = 1;
#ifdef ONPC
cin >> t;
while (t-- && cin) {
cin >> ans;
if (!cin) break;
#else
while (t-- && cin) {
#endif
if (solve()) break;
#ifdef ONPC
cout << "____________________" << endl;
#endif
}
return 0;
}
Compilation message
polygon.cpp: In function 'int solve()':
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:71:5: note: in expansion of macro 'debug'
71 | debug(name);
| ^~~~~
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:72:5: note: in expansion of macro 'debug'
72 | debug(adj, rev, inrel);
| ^~~~~
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:118:5: note: in expansion of macro 'debug'
118 | debug(res);
| ^~~~~
polygon.cpp: In lambda function:
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:124:13: note: in expansion of macro 'debug'
124 | debug("cycle", i, depth);
| ^~~~~
polygon.cpp: In lambda function:
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:129:13: note: in expansion of macro 'debug'
129 | debug("dfs", i);
| ^~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| 4 |
Correct |
256 ms |
25820 KB |
Output is correct |
| 5 |
Correct |
255 ms |
21780 KB |
Output is correct |
| 6 |
Correct |
271 ms |
26428 KB |
Output is correct |
| 7 |
Correct |
256 ms |
20952 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
339 ms |
23092 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
