#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define X first
#define Y second
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define test(args...) abc("[" + string(#args) + "]", args)
void abc() {cerr << endl;}
template <typename T, typename ...U> void abc(T a, U ...b) {
cerr << a << ' ', abc(b...);
}
template <typename T> void printv(T l, T r) {
while (l != r) cerr << *l << " \n"[++l == r];
}
const int mod = 1e9 + 7, N = 200000;
int main () {
ios::sync_with_stdio(false);
cin.tie(0);
int n, _id = 0;
cin >> n;
if (n & 1) return cout << -1 << endl, 0;
map <string, int> m1;
auto get = [&](string s) {
if (m1.count(s)) return m1[s];
return m1[s] = _id++;
};
vector <int> pt(n);
string s, t;
for (int i = 0; i < n; ++i) {
cin >> s >> t;
int u = get(s), v = get(t);
pt[u] = v;
}
int ans = n;
vector <bool> vis(n, false);
for (int i = 0; i < n; ++i) if (!vis[i]) {
int now = i, cur = 0;
while (!vis[now]) {
vis[now] = true;
cur++;
now = pt[now];
}
if (cur == 2) ans -= 2;
else ans -= cur / 2;
}
cout << ans << endl;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
0 ms |
204 KB |
Output is correct |
4 |
Correct |
195 ms |
8516 KB |
Output is correct |
5 |
Correct |
198 ms |
8584 KB |
Output is correct |
6 |
Correct |
186 ms |
8588 KB |
Output is correct |
7 |
Correct |
0 ms |
204 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
191 ms |
8424 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |