#include <bits/stdc++.h>
using namespace std;
const int N = 101010;
int n, go[N], vis[N], done[N]; bool dead[N];
vector<int> g[N];
map<string, int> mp;
map<int, int> cant;
array<int, 3> dfs(int p, int v) {
int s = 0, t = 1, sz = 1;
done[v]++;
for (int x : g[v]) {
if (p == x || dead[x])
continue;
if (cant[v] == x)
continue;
auto [y, z, w] = dfs(v, x);
s += max(y, z);
t += y;
sz += w;
}
return {s, t, sz};
}
int main() {
cin.tie(0); ios_base::sync_with_stdio(0);
cin >> n;
int sz = 0;
for (int i = 1; i <= n; i++) {
string s, t; cin >> s >> t;
int u = (mp[s] = (mp[s]) ? mp[s] : ++sz);
int v = (mp[t] = (mp[t]) ? mp[t] : ++sz);
go[u] = v;
g[u].push_back(v);
g[v].push_back(u);
}
if (n % 2 == 1)
return !(cout << -1);
int ans = 0;
vector<int> vtx;
for (int i = 1; i <= n; i++) {
if (vis[i] == 2)
continue;
int v = i;
while (!vis[v]) {
vtx.push_back(v);
vis[v] = 1;
v = go[v];
}
if (vis[v] == 1) {
// not using the edge
int s = 0;
cant[go[v]] = v;
cant[v] = go[v];
auto [x, y, z] = dfs(v, v);
s = z - max(x, y);
// using the edge
if (go[v] != v) {
int t = 1;
// cycle is length 2
if (v == go[go[v]])
t = 2;
dead[v] = 1;
dead[go[v]] = 1;
for (int x : g[v])
if (go[v] != x) {
auto [a, b, c] = dfs(v, x);
t += c - max(a, b);
}
for (int x : g[go[v]])
if (v != x && done[x] != 2) {
auto [a, b, c] = dfs(go[v], x);
t += c - max(a, b);
}
ans += max(s, t);
}
else
ans += s;
}
// initialize
for (int x : vtx)
vis[x] = 2;
vector<int>().swap(vtx);
}
cout << n - ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
1 ms |
2644 KB |
Output is correct |
4 |
Correct |
1 ms |
2644 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
1 ms |
2708 KB |
Output is correct |
8 |
Correct |
2 ms |
2644 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2704 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
2 ms |
2712 KB |
Output is correct |
14 |
Correct |
2 ms |
2644 KB |
Output is correct |
15 |
Correct |
2 ms |
2704 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
1 ms |
2644 KB |
Output is correct |
4 |
Correct |
353 ms |
33868 KB |
Output is correct |
5 |
Correct |
277 ms |
21736 KB |
Output is correct |
6 |
Correct |
355 ms |
36156 KB |
Output is correct |
7 |
Correct |
247 ms |
16156 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
282 ms |
18404 KB |
Output is correct |
2 |
Correct |
299 ms |
21960 KB |
Output is correct |
3 |
Correct |
181 ms |
19424 KB |
Output is correct |
4 |
Correct |
275 ms |
14124 KB |
Output is correct |
5 |
Correct |
259 ms |
32696 KB |
Output is correct |
6 |
Correct |
242 ms |
17216 KB |
Output is correct |
7 |
Correct |
292 ms |
17196 KB |
Output is correct |
8 |
Correct |
247 ms |
17796 KB |
Output is correct |
9 |
Correct |
223 ms |
16332 KB |
Output is correct |
10 |
Correct |
150 ms |
15180 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
2 ms |
2644 KB |
Output is correct |
14 |
Correct |
2 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
1 ms |
2644 KB |
Output is correct |
4 |
Correct |
1 ms |
2644 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
1 ms |
2708 KB |
Output is correct |
8 |
Correct |
2 ms |
2644 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2704 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
2 ms |
2712 KB |
Output is correct |
14 |
Correct |
2 ms |
2644 KB |
Output is correct |
15 |
Correct |
2 ms |
2704 KB |
Output is correct |
16 |
Correct |
1 ms |
2644 KB |
Output is correct |
17 |
Correct |
1 ms |
2644 KB |
Output is correct |
18 |
Correct |
1 ms |
2644 KB |
Output is correct |
19 |
Correct |
353 ms |
33868 KB |
Output is correct |
20 |
Correct |
277 ms |
21736 KB |
Output is correct |
21 |
Correct |
355 ms |
36156 KB |
Output is correct |
22 |
Correct |
247 ms |
16156 KB |
Output is correct |
23 |
Correct |
282 ms |
18404 KB |
Output is correct |
24 |
Correct |
299 ms |
21960 KB |
Output is correct |
25 |
Correct |
181 ms |
19424 KB |
Output is correct |
26 |
Correct |
275 ms |
14124 KB |
Output is correct |
27 |
Correct |
259 ms |
32696 KB |
Output is correct |
28 |
Correct |
242 ms |
17216 KB |
Output is correct |
29 |
Correct |
292 ms |
17196 KB |
Output is correct |
30 |
Correct |
247 ms |
17796 KB |
Output is correct |
31 |
Correct |
223 ms |
16332 KB |
Output is correct |
32 |
Correct |
150 ms |
15180 KB |
Output is correct |
33 |
Correct |
2 ms |
2644 KB |
Output is correct |
34 |
Correct |
2 ms |
2644 KB |
Output is correct |
35 |
Correct |
2 ms |
2644 KB |
Output is correct |
36 |
Correct |
2 ms |
2644 KB |
Output is correct |
37 |
Correct |
275 ms |
21324 KB |
Output is correct |
38 |
Correct |
291 ms |
21940 KB |
Output is correct |
39 |
Correct |
327 ms |
19680 KB |
Output is correct |
40 |
Correct |
288 ms |
19376 KB |
Output is correct |
41 |
Correct |
287 ms |
19592 KB |
Output is correct |
42 |
Correct |
322 ms |
20008 KB |
Output is correct |
43 |
Correct |
344 ms |
20024 KB |
Output is correct |
44 |
Correct |
339 ms |
20076 KB |
Output is correct |
45 |
Correct |
302 ms |
20164 KB |
Output is correct |
46 |
Correct |
289 ms |
20044 KB |
Output is correct |
47 |
Correct |
248 ms |
18672 KB |
Output is correct |
48 |
Correct |
304 ms |
20440 KB |
Output is correct |
49 |
Correct |
275 ms |
24132 KB |
Output is correct |
50 |
Correct |
212 ms |
21656 KB |
Output is correct |
51 |
Correct |
217 ms |
16284 KB |
Output is correct |
52 |
Correct |
313 ms |
34896 KB |
Output is correct |
53 |
Correct |
261 ms |
19596 KB |
Output is correct |
54 |
Correct |
293 ms |
19384 KB |
Output is correct |
55 |
Correct |
257 ms |
19912 KB |
Output is correct |
56 |
Correct |
212 ms |
18484 KB |
Output is correct |
57 |
Correct |
208 ms |
17360 KB |
Output is correct |
58 |
Correct |
2 ms |
2704 KB |
Output is correct |
59 |
Correct |
1 ms |
2644 KB |
Output is correct |
60 |
Correct |
2 ms |
2696 KB |
Output is correct |
61 |
Correct |
2 ms |
2644 KB |
Output is correct |
62 |
Correct |
3 ms |
2644 KB |
Output is correct |
63 |
Correct |
2 ms |
2644 KB |
Output is correct |
64 |
Correct |
3 ms |
2644 KB |
Output is correct |
65 |
Correct |
312 ms |
33840 KB |
Output is correct |
66 |
Correct |
261 ms |
21772 KB |
Output is correct |
67 |
Correct |
340 ms |
36064 KB |
Output is correct |
68 |
Correct |
259 ms |
16184 KB |
Output is correct |
69 |
Correct |
2 ms |
2708 KB |
Output is correct |
70 |
Correct |
2 ms |
2708 KB |
Output is correct |
71 |
Correct |
3 ms |
2644 KB |
Output is correct |
72 |
Correct |
1 ms |
2644 KB |
Output is correct |
73 |
Correct |
2 ms |
2772 KB |
Output is correct |
74 |
Correct |
2 ms |
2644 KB |
Output is correct |
75 |
Correct |
2 ms |
2700 KB |
Output is correct |
76 |
Correct |
2 ms |
2708 KB |
Output is correct |
77 |
Correct |
2 ms |
2644 KB |
Output is correct |
78 |
Correct |
2 ms |
2644 KB |
Output is correct |
79 |
Correct |
2 ms |
2644 KB |
Output is correct |
80 |
Correct |
2 ms |
2644 KB |
Output is correct |
81 |
Correct |
3 ms |
2644 KB |
Output is correct |
82 |
Correct |
2 ms |
2644 KB |
Output is correct |
83 |
Correct |
2 ms |
2644 KB |
Output is correct |