#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount
#define pb push_back
#define popf pop_front
#define popb pop_back
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
fastIO();
if (str != "") {
freopen((str + ".in").c_str(), "r", stdin);
freopen((str + ".out").c_str(), "w", stdout);
}
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 1e5 + 10;
int n, it = 1, ci = 1, answ, kent;
unordered_map<string, int> mp;
vector<int> adj[N];
int used[N], p[N], in[N];
bool happy[N];
void dfsCycle(int node, int parent) {
used[node] = 1, p[node] = parent;
for(auto i: adj[node]) {
if(i == parent) continue;
if(used[i] == 1) {
int curr = node, cnt = 1;
while(curr != i) {
curr = p[curr];
cnt++;
}
answ += cnt / 2;
if(cnt & 1) {
kent++;
}
} else if(!used[i]) {
dfsCycle(i, node);
}
}
used[node] = 2;
}
void solve_() {
cin >> n, mp.reserve(2 * n);
if(n & 1) {
printf("-1\n");
return;
}
for(int i = 1; i <= n; i++) {
string a, b; cin >> a >> b;
int ida, idb;
if(mp.find(a) == mp.end()) {
mp[a] = it++;
ida = it - 1;
} else {
ida = mp[a];
}
if(mp.find(b) == mp.end()) {
mp[b] = it++;
idb = it - 1;
} else {
idb = mp[b];
}
adj[ida].push_back(idb);
p[ida] = idb;
in[idb]++;
if(ida != idb && p[idb] == ida) {
happy[ida] = happy[idb] = true;
}
}
assert(it == n + 1);
queue<int> q;
for(int i = 1; i <= n; i++) {
if(!in[i]) {
q.push(i);
}
}
while(!q.empty()) {
auto u = q.front();
q.pop();
if(happy[p[u]]) {
happy[u] = true;
kent++;
continue;
}
happy[u] = happy[p[u]] = true;
answ++;
if (!happy[p[p[u]]]) {
in[p[p[u]]]--;
if (!in[p[p[u]]]) {
q.push(p[p[u]]);
}
}
}
for(int i = 1; i <= n; i++) {
if(!happy[i]) {
// cycles
dfsCycle(i, 0);
}
}
assert(kent % 2 == 0);
answ += kent;
printf("%d\n", answ);
}
int main() {
setIO("");
auto solve = [&](int test_case)-> void {
while(test_case--) {
solve_();
}
};
int test_cases = 1;
solve(test_cases);
return 0;
}
Compilation message
polygon.cpp: In function 'void setIO(std::string)':
polygon.cpp:63:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
63 | freopen((str + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
polygon.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
64 | freopen((str + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
2 ms |
2688 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2592 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
1 ms |
2644 KB |
Output is correct |
14 |
Correct |
2 ms |
2772 KB |
Output is correct |
15 |
Correct |
2 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
88 ms |
23736 KB |
Output is correct |
5 |
Correct |
83 ms |
16988 KB |
Output is correct |
6 |
Correct |
107 ms |
24768 KB |
Output is correct |
7 |
Correct |
3 ms |
4232 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
87 ms |
15648 KB |
Output is correct |
2 |
Correct |
79 ms |
16656 KB |
Output is correct |
3 |
Correct |
46 ms |
16908 KB |
Output is correct |
4 |
Correct |
2 ms |
4308 KB |
Output is correct |
5 |
Correct |
80 ms |
16636 KB |
Output is correct |
6 |
Correct |
71 ms |
16836 KB |
Output is correct |
7 |
Correct |
67 ms |
17164 KB |
Output is correct |
8 |
Correct |
66 ms |
17144 KB |
Output is correct |
9 |
Correct |
64 ms |
16984 KB |
Output is correct |
10 |
Correct |
46 ms |
16672 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 |
1 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
2 ms |
2688 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2592 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
1 ms |
2644 KB |
Output is correct |
14 |
Correct |
2 ms |
2772 KB |
Output is correct |
15 |
Correct |
2 ms |
2644 KB |
Output is correct |
16 |
Correct |
2 ms |
2644 KB |
Output is correct |
17 |
Correct |
1 ms |
2644 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Correct |
88 ms |
23736 KB |
Output is correct |
20 |
Correct |
83 ms |
16988 KB |
Output is correct |
21 |
Correct |
107 ms |
24768 KB |
Output is correct |
22 |
Correct |
3 ms |
4232 KB |
Output is correct |
23 |
Correct |
87 ms |
15648 KB |
Output is correct |
24 |
Correct |
79 ms |
16656 KB |
Output is correct |
25 |
Correct |
46 ms |
16908 KB |
Output is correct |
26 |
Correct |
2 ms |
4308 KB |
Output is correct |
27 |
Correct |
80 ms |
16636 KB |
Output is correct |
28 |
Correct |
71 ms |
16836 KB |
Output is correct |
29 |
Correct |
67 ms |
17164 KB |
Output is correct |
30 |
Correct |
66 ms |
17144 KB |
Output is correct |
31 |
Correct |
64 ms |
16984 KB |
Output is correct |
32 |
Correct |
46 ms |
16672 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 |
1 ms |
2644 KB |
Output is correct |
37 |
Correct |
77 ms |
16708 KB |
Output is correct |
38 |
Correct |
71 ms |
16768 KB |
Output is correct |
39 |
Correct |
77 ms |
17156 KB |
Output is correct |
40 |
Correct |
64 ms |
16892 KB |
Output is correct |
41 |
Correct |
64 ms |
16844 KB |
Output is correct |
42 |
Correct |
69 ms |
16808 KB |
Output is correct |
43 |
Correct |
90 ms |
16844 KB |
Output is correct |
44 |
Correct |
89 ms |
16856 KB |
Output is correct |
45 |
Correct |
64 ms |
16732 KB |
Output is correct |
46 |
Correct |
68 ms |
16840 KB |
Output is correct |
47 |
Correct |
58 ms |
16912 KB |
Output is correct |
48 |
Correct |
75 ms |
17104 KB |
Output is correct |
49 |
Correct |
72 ms |
16672 KB |
Output is correct |
50 |
Correct |
44 ms |
16972 KB |
Output is correct |
51 |
Correct |
2 ms |
4308 KB |
Output is correct |
52 |
Correct |
71 ms |
16632 KB |
Output is correct |
53 |
Correct |
65 ms |
16844 KB |
Output is correct |
54 |
Correct |
91 ms |
17100 KB |
Output is correct |
55 |
Correct |
67 ms |
17212 KB |
Output is correct |
56 |
Correct |
57 ms |
16872 KB |
Output is correct |
57 |
Correct |
47 ms |
16628 KB |
Output is correct |
58 |
Correct |
2 ms |
2644 KB |
Output is correct |
59 |
Correct |
1 ms |
2644 KB |
Output is correct |
60 |
Correct |
2 ms |
2644 KB |
Output is correct |
61 |
Correct |
2 ms |
2644 KB |
Output is correct |
62 |
Correct |
2 ms |
2684 KB |
Output is correct |
63 |
Correct |
2 ms |
2644 KB |
Output is correct |
64 |
Correct |
2 ms |
2644 KB |
Output is correct |
65 |
Correct |
88 ms |
23772 KB |
Output is correct |
66 |
Correct |
76 ms |
17000 KB |
Output is correct |
67 |
Correct |
88 ms |
24712 KB |
Output is correct |
68 |
Correct |
2 ms |
4308 KB |
Output is correct |
69 |
Correct |
2 ms |
2684 KB |
Output is correct |
70 |
Correct |
1 ms |
2644 KB |
Output is correct |
71 |
Correct |
2 ms |
2644 KB |
Output is correct |
72 |
Correct |
1 ms |
2644 KB |
Output is correct |
73 |
Correct |
2 ms |
2644 KB |
Output is correct |
74 |
Correct |
2 ms |
2644 KB |
Output is correct |
75 |
Correct |
2 ms |
2644 KB |
Output is correct |
76 |
Correct |
1 ms |
2684 KB |
Output is correct |
77 |
Correct |
1 ms |
2644 KB |
Output is correct |
78 |
Correct |
2 ms |
2684 KB |
Output is correct |
79 |
Correct |
1 ms |
2644 KB |
Output is correct |
80 |
Correct |
2 ms |
2684 KB |
Output is correct |
81 |
Correct |
2 ms |
2684 KB |
Output is correct |
82 |
Correct |
1 ms |
2644 KB |
Output is correct |
83 |
Correct |
1 ms |
2644 KB |
Output is correct |