// Muallif: Mansuraliyev Husanboy Murotali o'g'li >> NamPS
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ios ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define all(a) a.begin(), a.end()
#define F first
#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define S second
#define fp(a,i,c) for(int (a) = (i); (a) < (c); (a)++)
#define fm(a,i,c) for(int (a) = (i); (a) >= (c); (a)--)
// 0-9 >> 48-57; A-Z>>65-90 and a-z>>97-122 respectively;
const int MX=1e5+5;
vector<int> g[MX];
int vis[MX];
int dfs(int i){
vis[i]=1;
int s=0;
for(auto u:g[i]){
if(vis[u]==1){
continue;
}
s+=dfs(u)+1;
}
return s;
}
void solve(){
int n; cin>>n;
map<string,int> mp;
int cur=1;
for(int i=0;i<n;i++){
string a,b; cin>>a>>b;
if(mp[a]==0) mp[a]=cur,cur++;
if(mp[b]==0) mp[b]=cur,cur++;
g[mp[a]].push_back(mp[b]);
}
if(n%2){
cout<<"-1\n";return;
}
int k=0;
ll ans=0;
for(int i=1;i<=n;i++){
if(vis[i]) continue;
int s=dfs(i)+1;
k+=s%2;
ans+=s/2;
}
cout<<ans+k/2<<"\n";
}
int main(){
ios;
solve();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
198 ms |
13900 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |