#include <bits/stdc++.h>
#include <math.h>
//in the name of god,aka allah
//**gray sety orz**
using namespace std;
#define pi pair<long long , long long>
#define pii pair<long long , pair<long long , long long>>
const int maxm = 5e5;
const long long mod = 1e9 + 7 ;
typedef long long ll;
ll l,r,mid;
ll n,m;
ll darage[maxm] , ss , mm;
queue<int> q;
bool vis[maxm];
ll pedaret[maxm];
set<string> st;
ll rp[maxm];
map<string,ll> mp;
inline void bfs(){
mid = 0;
while(q.size()){
l = q.front();
q.pop();
mid++;
vis[l]=1;
if(!vis[pedaret[l]]){
if(!vis[pedaret[pedaret[l]]]&&darage[pedaret[pedaret[l]]]-1==0) q.push(pedaret[pedaret[l]]);
vis[pedaret[l]]=1;
}
}
return;
}
int pe(string s){
if(st.find(s)==st.end()) mp.insert({s,mp.size()}) , st.insert(s);
return mp[s];
}
int main() {
ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
cin>>n;
if(n%2) return cout<<-1,0;
for(int i = 0; i<n; i++){
string s,t;
cin>>s>>t;
l=pe(s);
r=pe(t);
pedaret[l]=r;
darage[r]++;
}
for(int i=0; i<n; i++){
if(pedaret[pedaret[i]]==i && pedaret[i]!=i){
vis[i]=1,vis[pedaret[i]]=1;
}
}
for(int i=0; i<n; i++) {
if(!vis[i] && darage[i]==0) q.push(i);
}
bfs();
for(int i=0; i<n; i++){
if(!vis[i]){
r=1;
ss=pedaret[i];
while (ss!=i) r++ , ss=pedaret[ss];
mid+=(r+1)/2;
}
}
cout<<mid;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
2083 ms |
19904 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |