#include <bits/stdc++.h>
using namespace std;
#define MAX 200007
#define int long long
bitset<MAX> visited;
int curSz = 0;
void dfs(int x, int adj[]){
if (visited[x]) return;
curSz++;
visited[x] = 1;
dfs(adj[x], adj);
}
main(){
int n; cin >> n;
if (n % 2 == 1) {cout << -1; return 0;}
map<string, string> init;
map<string, int> indexed;
int adj[n];
for (int x = 0; x < n; x++){
string a, b; cin >> a >> b;
init[a] = b;
}
string name[n]; int ptr = 0;
for (auto y : init){
name[ptr] = y.first;
indexed[y.first] = ptr;
ptr++;
}
int indeg[n]; memset(indeg, 0, sizeof(indeg));
for (auto y : init){
adj[indexed[y.first]] = indexed[y.second];
if (y.first != y.second) indeg[indexed[y.second]]++;
}
bitset<MAX> taken;
queue<int> process;
for (int x = 0; x < n; x++){
if (indeg[x] == 0) process.push(x);
if (x != adj[x] && adj[adj[x]] == x) taken[x] = 1, taken[adj[x]] = 1;
}
int ans = 0;
while (!process.empty()){
int x = process.front();
process.pop();
if (taken[x]) continue;
if (taken[adj[x]]){
adj[x] = x;
//indeg decrease, but doesn't matter since already taken
continue;
}
ans++;
indeg[adj[adj[x]]]--;
if (indeg[adj[adj[x]]] == 0) process.push(adj[adj[x]]);
adj[adj[x]] = x;
taken[x] = 1;
taken[adj[x]] = 1;
}
for (int x = 0; x < n; x++){
if (!taken[x]){
curSz = 0;
dfs(x, adj);
ans += (curSz+1)/2;
}
}
cout << ans;
}
Compilation message
polygon.cpp:16:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
16 | main(){
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
1 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
1 ms |
344 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
348 KB |
Output is correct |
| 11 |
Correct |
0 ms |
348 KB |
Output is correct |
| 12 |
Correct |
1 ms |
348 KB |
Output is correct |
| 13 |
Correct |
1 ms |
344 KB |
Output is correct |
| 14 |
Correct |
1 ms |
348 KB |
Output is correct |
| 15 |
Correct |
1 ms |
456 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
315 ms |
26052 KB |
Output is correct |
| 5 |
Correct |
275 ms |
25940 KB |
Output is correct |
| 6 |
Correct |
265 ms |
25936 KB |
Output is correct |
| 7 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
254 ms |
23908 KB |
Output is correct |
| 2 |
Correct |
298 ms |
23908 KB |
Output is correct |
| 3 |
Correct |
200 ms |
24680 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
288 ms |
23908 KB |
Output is correct |
| 6 |
Correct |
282 ms |
24164 KB |
Output is correct |
| 7 |
Correct |
316 ms |
24300 KB |
Output is correct |
| 8 |
Correct |
274 ms |
24444 KB |
Output is correct |
| 9 |
Correct |
294 ms |
24680 KB |
Output is correct |
| 10 |
Correct |
223 ms |
24524 KB |
Output is correct |
| 11 |
Correct |
1 ms |
348 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
1 ms |
344 KB |
Output is correct |
| 14 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
1 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
1 ms |
344 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
348 KB |
Output is correct |
| 11 |
Correct |
0 ms |
348 KB |
Output is correct |
| 12 |
Correct |
1 ms |
348 KB |
Output is correct |
| 13 |
Correct |
1 ms |
344 KB |
Output is correct |
| 14 |
Correct |
1 ms |
348 KB |
Output is correct |
| 15 |
Correct |
1 ms |
456 KB |
Output is correct |
| 16 |
Correct |
1 ms |
348 KB |
Output is correct |
| 17 |
Correct |
1 ms |
348 KB |
Output is correct |
| 18 |
Correct |
1 ms |
348 KB |
Output is correct |
| 19 |
Correct |
315 ms |
26052 KB |
Output is correct |
| 20 |
Correct |
275 ms |
25940 KB |
Output is correct |
| 21 |
Correct |
265 ms |
25936 KB |
Output is correct |
| 22 |
Correct |
1 ms |
348 KB |
Output is correct |
| 23 |
Correct |
254 ms |
23908 KB |
Output is correct |
| 24 |
Correct |
298 ms |
23908 KB |
Output is correct |
| 25 |
Correct |
200 ms |
24680 KB |
Output is correct |
| 26 |
Correct |
0 ms |
348 KB |
Output is correct |
| 27 |
Correct |
288 ms |
23908 KB |
Output is correct |
| 28 |
Correct |
282 ms |
24164 KB |
Output is correct |
| 29 |
Correct |
316 ms |
24300 KB |
Output is correct |
| 30 |
Correct |
274 ms |
24444 KB |
Output is correct |
| 31 |
Correct |
294 ms |
24680 KB |
Output is correct |
| 32 |
Correct |
223 ms |
24524 KB |
Output is correct |
| 33 |
Correct |
1 ms |
348 KB |
Output is correct |
| 34 |
Correct |
0 ms |
348 KB |
Output is correct |
| 35 |
Correct |
1 ms |
344 KB |
Output is correct |
| 36 |
Correct |
1 ms |
348 KB |
Output is correct |
| 37 |
Correct |
279 ms |
25920 KB |
Output is correct |
| 38 |
Correct |
286 ms |
26328 KB |
Output is correct |
| 39 |
Correct |
297 ms |
26324 KB |
Output is correct |
| 40 |
Correct |
258 ms |
26320 KB |
Output is correct |
| 41 |
Correct |
302 ms |
26308 KB |
Output is correct |
| 42 |
Correct |
254 ms |
26328 KB |
Output is correct |
| 43 |
Correct |
277 ms |
26324 KB |
Output is correct |
| 44 |
Correct |
300 ms |
26388 KB |
Output is correct |
| 45 |
Correct |
309 ms |
26284 KB |
Output is correct |
| 46 |
Correct |
228 ms |
26196 KB |
Output is correct |
| 47 |
Correct |
272 ms |
26440 KB |
Output is correct |
| 48 |
Correct |
265 ms |
26176 KB |
Output is correct |
| 49 |
Correct |
311 ms |
26120 KB |
Output is correct |
| 50 |
Correct |
215 ms |
26836 KB |
Output is correct |
| 51 |
Correct |
1 ms |
344 KB |
Output is correct |
| 52 |
Correct |
307 ms |
25940 KB |
Output is correct |
| 53 |
Correct |
295 ms |
26488 KB |
Output is correct |
| 54 |
Correct |
267 ms |
26340 KB |
Output is correct |
| 55 |
Correct |
234 ms |
26444 KB |
Output is correct |
| 56 |
Correct |
256 ms |
26540 KB |
Output is correct |
| 57 |
Correct |
203 ms |
26784 KB |
Output is correct |
| 58 |
Correct |
1 ms |
500 KB |
Output is correct |
| 59 |
Correct |
1 ms |
348 KB |
Output is correct |
| 60 |
Correct |
1 ms |
348 KB |
Output is correct |
| 61 |
Correct |
1 ms |
348 KB |
Output is correct |
| 62 |
Correct |
1 ms |
600 KB |
Output is correct |
| 63 |
Correct |
0 ms |
344 KB |
Output is correct |
| 64 |
Correct |
1 ms |
348 KB |
Output is correct |
| 65 |
Correct |
244 ms |
25936 KB |
Output is correct |
| 66 |
Correct |
269 ms |
26184 KB |
Output is correct |
| 67 |
Correct |
282 ms |
26324 KB |
Output is correct |
| 68 |
Correct |
1 ms |
472 KB |
Output is correct |
| 69 |
Correct |
1 ms |
348 KB |
Output is correct |
| 70 |
Correct |
1 ms |
348 KB |
Output is correct |
| 71 |
Correct |
1 ms |
348 KB |
Output is correct |
| 72 |
Correct |
1 ms |
348 KB |
Output is correct |
| 73 |
Correct |
1 ms |
348 KB |
Output is correct |
| 74 |
Correct |
1 ms |
348 KB |
Output is correct |
| 75 |
Correct |
1 ms |
460 KB |
Output is correct |
| 76 |
Correct |
1 ms |
348 KB |
Output is correct |
| 77 |
Correct |
1 ms |
348 KB |
Output is correct |
| 78 |
Correct |
1 ms |
348 KB |
Output is correct |
| 79 |
Correct |
1 ms |
348 KB |
Output is correct |
| 80 |
Correct |
1 ms |
348 KB |
Output is correct |
| 81 |
Correct |
1 ms |
344 KB |
Output is correct |
| 82 |
Correct |
1 ms |
460 KB |
Output is correct |
| 83 |
Correct |
1 ms |
348 KB |
Output is correct |
