#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define f first
#define s second
#define pi pair<int,int>
const int MAX = 2e5;
int n;
map<string,int>m;
vector<int>g[MAX];
int love[MAX];
int indegree[MAX];
int visited[MAX];
int main(){
int n;
cin>> n;
string from, to;
int k = 1;
if(n%2){
cout << -1 << endl;
return 0;
}
int a,b;
for(int i = 0; i < n; i++){
cin >> from >> to;
if(m[from]==0) {
// cout << from << " " << k << endl;
m[from]=k++;
}
if(m[to]==0){
// cout << to << " " << k << endl;
m[to]=k++;
}
a = m[from], b= m[to];
love[a]=b;
if(love[b]==a && a!=b){
visited[a]= visited[b]=1;
}
g[a].pb(b);
indegree[b]++;
}
queue<int>q;
for(int i = 1; i <= n; i++){
if(indegree[i]==0 && visited[i]==0){
q.push(i);
}
}
ll ans = 0;
while(!q.empty()){
int from = q.front();
q.pop();
// cout << from << " " << ans<< endl;
for(int to : g[from]){
indegree[to]--;
if(!visited[to]){
q.push(to);
if(visited[from])continue;
love[from]=to;
ans++;
visited[from]= visited[to] =1;
}
}
}
// ans /=2;
for(int i = 1; i <= n; i++){
if(!visited[i] &&!visited[love[i]]&& love[i]!=i && love[i]!=0) {
ans++;
visited[i]=1
visited[love[i]]=1;
}
}
for(int i = 1; i <= n; i++){
if(!visited[i]) {
ans++;
}
}
cout << ans << endl;
}
Compilation message
polygon.cpp: In function 'int main()':
polygon.cpp:81:29: error: expected ';' before 'visited'
81 | visited[i]=1
| ^
| ;
82 | visited[love[i]]=1;
| ~~~~~~~
