#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>
#define cerr cout
#ifdef ONPC
#include "t_debug.cpp"
#else
#define debug(...) 42
#endif
#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;
auto set_love = [&](int from, int to) {
rev[adj[from]].erase(from);
rev[to].insert(from);
adj[from] = to;
};
auto check = [&](int i) {
if (rev[i].empty()) {
if (inrel[adj[i]]) {set_love(i, i); return false; }
else {unloved.insert(i); return true; }
}
return false;
};
function<void()> action = [&]() {
for (int i = 0; i < n; i++) {
check(i);
}
while (!unloved.empty()) {
int i = *unloved.begin();
if (check(i)) {
int j = adj[i];
// remove those who love j
for (int k : rev[j]) {
adj[k] = k;
rev[k].insert(k);
}
int dangling = adj[j];
rev[j].clear();
set_love(j, i);
set_love(i, j);
inrel[j] = inrel[i] = 1;
inrel_count += 2;
res++;
check(dangling);
}
debug(i, adj, rev, inrel, unloved);
unloved.erase(i);
}
};
action();
vi adj_p = adj;
debug("run 2");
action();
assert(adj == adj_p);
for (int i = 0; i < n; i++) {
assert(rev[i].size() == 1);
}
}
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:72:5: note: in expansion of macro 'debug'
72 | debug(name);
| ^~~~~
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:73:5: note: in expansion of macro 'debug'
73 | debug(adj, rev, inrel);
| ^~~~~
polygon.cpp: In lambda function:
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:115:17: note: in expansion of macro 'debug'
115 | debug(i, adj, rev, inrel, unloved);
| ^~~~~
polygon.cpp: In function 'int solve()':
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:122:9: note: in expansion of macro 'debug'
122 | debug("run 2");
| ^~~~~
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:130:5: note: in expansion of macro 'debug'
130 | debug(res);
| ^~~~~
polygon.cpp: In lambda function:
polygon.cpp:11:24: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 42
| ^~
polygon.cpp:136:13: note: in expansion of macro 'debug'
136 | 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:141:13: note: in expansion of macro 'debug'
141 | debug("dfs", i);
| ^~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
324 KB |
Output is correct |
8 |
Correct |
1 ms |
320 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
324 KB |
Output is correct |
4 |
Correct |
269 ms |
26052 KB |
Output is correct |
5 |
Correct |
278 ms |
22100 KB |
Output is correct |
6 |
Correct |
262 ms |
26732 KB |
Output is correct |
7 |
Correct |
274 ms |
21280 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
304 ms |
23304 KB |
Output is correct |
2 |
Correct |
357 ms |
24556 KB |
Output is correct |
3 |
Correct |
231 ms |
23832 KB |
Output is correct |
4 |
Correct |
274 ms |
23168 KB |
Output is correct |
5 |
Correct |
353 ms |
23804 KB |
Output is correct |
6 |
Correct |
344 ms |
26228 KB |
Output is correct |
7 |
Correct |
389 ms |
26352 KB |
Output is correct |
8 |
Correct |
296 ms |
25660 KB |
Output is correct |
9 |
Correct |
347 ms |
27804 KB |
Output is correct |
10 |
Correct |
251 ms |
33260 KB |
Output is correct |
11 |
Correct |
1 ms |
324 KB |
Output is correct |
12 |
Correct |
1 ms |
324 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
324 KB |
Output is correct |
8 |
Correct |
1 ms |
320 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
1 ms |
212 KB |
Output is correct |
16 |
Correct |
1 ms |
212 KB |
Output is correct |
17 |
Correct |
1 ms |
212 KB |
Output is correct |
18 |
Correct |
1 ms |
324 KB |
Output is correct |
19 |
Correct |
269 ms |
26052 KB |
Output is correct |
20 |
Correct |
278 ms |
22100 KB |
Output is correct |
21 |
Correct |
262 ms |
26732 KB |
Output is correct |
22 |
Correct |
274 ms |
21280 KB |
Output is correct |
23 |
Correct |
304 ms |
23304 KB |
Output is correct |
24 |
Correct |
357 ms |
24556 KB |
Output is correct |
25 |
Correct |
231 ms |
23832 KB |
Output is correct |
26 |
Correct |
274 ms |
23168 KB |
Output is correct |
27 |
Correct |
353 ms |
23804 KB |
Output is correct |
28 |
Correct |
344 ms |
26228 KB |
Output is correct |
29 |
Correct |
389 ms |
26352 KB |
Output is correct |
30 |
Correct |
296 ms |
25660 KB |
Output is correct |
31 |
Correct |
347 ms |
27804 KB |
Output is correct |
32 |
Correct |
251 ms |
33260 KB |
Output is correct |
33 |
Correct |
1 ms |
324 KB |
Output is correct |
34 |
Correct |
1 ms |
324 KB |
Output is correct |
35 |
Correct |
1 ms |
212 KB |
Output is correct |
36 |
Correct |
1 ms |
212 KB |
Output is correct |
37 |
Correct |
301 ms |
24384 KB |
Output is correct |
38 |
Correct |
323 ms |
26032 KB |
Output is correct |
39 |
Correct |
330 ms |
25984 KB |
Output is correct |
40 |
Correct |
303 ms |
26232 KB |
Output is correct |
41 |
Correct |
332 ms |
26304 KB |
Output is correct |
42 |
Correct |
328 ms |
25664 KB |
Output is correct |
43 |
Correct |
335 ms |
25576 KB |
Output is correct |
44 |
Correct |
316 ms |
25576 KB |
Output is correct |
45 |
Correct |
308 ms |
25616 KB |
Output is correct |
46 |
Correct |
311 ms |
25600 KB |
Output is correct |
47 |
Correct |
323 ms |
27460 KB |
Output is correct |
48 |
Correct |
338 ms |
24984 KB |
Output is correct |
49 |
Correct |
281 ms |
24608 KB |
Output is correct |
50 |
Correct |
230 ms |
23900 KB |
Output is correct |
51 |
Correct |
286 ms |
23276 KB |
Output is correct |
52 |
Correct |
292 ms |
24004 KB |
Output is correct |
53 |
Correct |
332 ms |
26184 KB |
Output is correct |
54 |
Correct |
314 ms |
26244 KB |
Output is correct |
55 |
Correct |
287 ms |
25552 KB |
Output is correct |
56 |
Correct |
318 ms |
27568 KB |
Output is correct |
57 |
Correct |
286 ms |
33276 KB |
Output is correct |
58 |
Correct |
1 ms |
212 KB |
Output is correct |
59 |
Correct |
1 ms |
212 KB |
Output is correct |
60 |
Correct |
1 ms |
324 KB |
Output is correct |
61 |
Correct |
1 ms |
212 KB |
Output is correct |
62 |
Correct |
1 ms |
324 KB |
Output is correct |
63 |
Correct |
1 ms |
212 KB |
Output is correct |
64 |
Correct |
1 ms |
320 KB |
Output is correct |
65 |
Correct |
311 ms |
27860 KB |
Output is correct |
66 |
Correct |
273 ms |
23880 KB |
Output is correct |
67 |
Correct |
280 ms |
28488 KB |
Output is correct |
68 |
Correct |
274 ms |
23224 KB |
Output is correct |
69 |
Correct |
1 ms |
324 KB |
Output is correct |
70 |
Correct |
1 ms |
212 KB |
Output is correct |
71 |
Correct |
1 ms |
212 KB |
Output is correct |
72 |
Correct |
1 ms |
212 KB |
Output is correct |
73 |
Correct |
1 ms |
212 KB |
Output is correct |
74 |
Correct |
1 ms |
212 KB |
Output is correct |
75 |
Correct |
1 ms |
324 KB |
Output is correct |
76 |
Correct |
1 ms |
212 KB |
Output is correct |
77 |
Correct |
1 ms |
212 KB |
Output is correct |
78 |
Correct |
1 ms |
212 KB |
Output is correct |
79 |
Correct |
1 ms |
212 KB |
Output is correct |
80 |
Correct |
1 ms |
212 KB |
Output is correct |
81 |
Correct |
1 ms |
212 KB |
Output is correct |
82 |
Correct |
1 ms |
212 KB |
Output is correct |
83 |
Correct |
1 ms |
324 KB |
Output is correct |