#include <cstdio>
#include <vector>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std;
typedef long long lint;
typedef pair<int,lint> pi;
int n;
vector<int> graph[200005];
int deg[200005];
int piv;
int cycle_num[200005];
int tree_num[200005];
int get_cycle[200005];
pi cycle_ret[200005];
long long freq[200005];
void label_graph(){
queue<int> q;
for (int i=1; i<=n; i++) {
if(deg[i] == 1){
q.push(i);
}
}
while (!q.empty()) {
int x = q.front();
q.pop();
deg[x] = 0;
for (int &i : graph[x]){
if(deg[i]){
deg[i]--;
if(deg[i] == 1){
q.push(i);
}
}
}
}
for (int i=1; i<=n; i++) {
if(deg[i]){
q.push(i);
break;
}
}
while (!q.empty()) {
int x = q.front();
q.pop();
cycle_num[x] = ++piv;
get_cycle[cycle_num[x]] = x;
tree_num[x] = cycle_num[x];
for (int &i : graph[x]){
if(deg[i] && !cycle_num[i]){
q.push(i);
break;
}
}
}
for (int i=1; i<=n; i++) {
if(cycle_num[i]){
q.push(i);
while (!q.empty()) {
int x = q.front();
q.pop();
for (int &i : graph[x]){
if(!tree_num[i]){
tree_num[i] = tree_num[x];
q.push(i);
}
}
}
}
}
}
bool cmp(pi a, pi b){
return a.first > b.first;
}
pi f(int x, int pa){
vector<pi> sub;
for (int &i : graph[x]){
if(i == pa) continue;
if(cycle_num[i]) continue;
pi t = f(i,x);
t.first++;
sub.push_back(t);
}
sort(sub.begin(),sub.end(),cmp);
if(sub.size() == 0) return pi(0,1);
if(sub.size() == 1){
freq[sub[0].first] += sub[0].second;
return sub[0];
}
if(sub[0].first == sub[1].first){
pi t(sub[0].first,0);
for (int i=0; i<sub.size(); i++) {
if(sub[0].first == sub[i].first) t.second += sub[i].second;
}
long long sum = 1ll * t.second * t.second;
for (int i=0; i<sub.size(); i++) {
if(sub[0].first == sub[i].first) sum -= 1ll * sub[i].second * sub[i].second;
}
sum /= 2;
freq[t.first * 2] += sum;
return t;
}
int low_sub = 0;
for (int i=1; i<sub.size(); i++) {
if(sub[1].first == sub[i].first) low_sub += sub[i].second;
}
freq[sub[0].first + sub[1].first] += 1ll * low_sub * sub[0].second;
return sub[0];
}
int main(){
scanf("%d",&n);
for (int i=0; i<n; i++) {
int s,e;
scanf("%d %d",&s,&e);
graph[s].push_back(e);
graph[e].push_back(s);
deg[s]++;
deg[e]++;
}
label_graph();
for (int i=1; i<=n; i++) {
if(cycle_num[i]){
cycle_ret[i] = f(i,0);
}
}
for (int i=1; i<=piv; i++) {
for (int j=i+1; j<=piv; j++) {
if(j-i == n - j + i){
int lng = cycle_ret[i].first + cycle_ret[j].first + j - i;
freq[lng] += cycle_ret[i].second * cycle_ret[j].second * 2ll;
}
else{
int lng = cycle_ret[i].first + cycle_ret[j].first + min(j-i,n-j+i);
freq[lng] += cycle_ret[i].second * cycle_ret[j].second;
}
}
}
for (int i=n; i; i--) {
if(freq[i]){
printf("%lld",freq[i]);
return 0;
}
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
14084 KB |
Output is correct |
2 |
Incorrect |
3 ms |
14084 KB |
Output isn't correct |
3 |
Incorrect |
3 ms |
14084 KB |
Output isn't correct |
4 |
Incorrect |
1 ms |
14084 KB |
Output isn't correct |
5 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
6 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
7 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
8 |
Incorrect |
3 ms |
14084 KB |
Output isn't correct |
9 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
10 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
11 |
Incorrect |
3 ms |
14084 KB |
Output isn't correct |
12 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
13 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
14 |
Incorrect |
4 ms |
14084 KB |
Output isn't correct |
15 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
14084 KB |
Output is correct |
2 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
3 |
Incorrect |
3 ms |
14084 KB |
Output isn't correct |
4 |
Incorrect |
0 ms |
14084 KB |
Output isn't correct |
5 |
Incorrect |
3 ms |
14216 KB |
Output isn't correct |
6 |
Incorrect |
4 ms |
14396 KB |
Output isn't correct |
7 |
Correct |
4 ms |
14216 KB |
Output is correct |
8 |
Incorrect |
3 ms |
14216 KB |
Output isn't correct |
9 |
Incorrect |
6 ms |
14216 KB |
Output isn't correct |
10 |
Incorrect |
3 ms |
14216 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
78 ms |
17248 KB |
Output is correct |
2 |
Incorrect |
89 ms |
17644 KB |
Output isn't correct |
3 |
Execution timed out |
1500 ms |
17248 KB |
Program timed out |
4 |
Incorrect |
53 ms |
17380 KB |
Output isn't correct |
5 |
Incorrect |
56 ms |
17512 KB |
Output isn't correct |
6 |
Correct |
172 ms |
20020 KB |
Output is correct |
7 |
Incorrect |
134 ms |
19164 KB |
Output isn't correct |
8 |
Incorrect |
121 ms |
20812 KB |
Output isn't correct |
9 |
Incorrect |
118 ms |
20812 KB |
Output isn't correct |
10 |
Incorrect |
165 ms |
21208 KB |
Output isn't correct |
11 |
Incorrect |
111 ms |
27200 KB |
Output isn't correct |
12 |
Incorrect |
143 ms |
27512 KB |
Output isn't correct |