#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
// #include "temp.cpp"
#include <cstdio>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) x.clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount
#define pb push_back
#define pf push_front
#define popf pop_front
#define popb pop_back
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
template <class T> void print(set <T> v);
template <class T> void print(vector <T> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T, class V> void print(pair <T, V> p);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque<T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(unordered_map<T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
fastIO();
if (str != "" && str != "input") {
freopen((str + ".in").c_str(), "r", stdin);
freopen((str + ".out").c_str(), "w", stdout);
}
if(str == "input") {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const long long inf = 1e15;
const int N = 2e5 + 10;
vector<int> adj[N];
pair<long long, long long> combine(pair<long long, long long> a, pair<long long, long long> b) {
if(a.first == b.first) {
a.second += b.second;
return a;
} else if(a.first > b.first) {
return a;
} else {
return b;
}
}
// for cycle
bool in_cycle[N];
int n, vis[N], p[N];
vector<int> cycle;
bool is_cycle = false;
void dfsCycle(int node, int parent) {
vis[node] = 1, p[node] = parent;
for(auto i: adj[node]) {
if(i == parent) continue;
if(vis[i] == 1) {
int curr = node;
while(curr != i) {
cycle.push_back(curr);
curr = p[curr];
}
cycle.push_back(curr);
is_cycle = true;
return;
} else if(!vis[i]) {
dfsCycle(i, node);
}
if(is_cycle) {
return;
}
}
vis[node] = 2;
}
// for trees
pair<long long, long long> dp[N];
pair<long long, long long> ans = {0, 0};
void dfs_depth(int node, int parent) {
dp[node] = {0, 1};
int cnt = 0;
for(auto i: adj[node]) {
if(i == parent || in_cycle[i]) continue;
dfs_depth(i, node);
cnt++;
pair<long long, long long> sub = dp[i];
sub.first++;
if(cnt == 1) {
dp[node] = sub;
}
else {
pair<long long, long long> sub_x = {dp[node].first + dp[i].first + 1, dp[node].second * dp[i].second};
dp[node] = combine(dp[node], sub);
ans = combine(ans, sub_x);
}
ans = combine(ans, dp[node]);
}
}
void solve_() {
cin >> n;
for(int i = 1; i <= n; i++) {
int a, b; cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
dfsCycle(1, 0);
for(auto i: cycle) {
in_cycle[i] = true;
}
for(auto i: cycle) {
dfs_depth(i, 0);
}
int sz = sz(cycle);
set<pair<long long, long long>> st;
for(int i = 0; i < sz + sz / 2; i++) {
if(i >= sz / 2) {
pair<long long, long long> curr = {dp[cycle[i % sz]].first + i + st.rbegin()->first, 0};
ans = combine(ans, curr);
st.erase({dp[cycle[i - sz / 2]].first - (i - sz / 2), i - sz / 2});
}
st.insert({dp[cycle[i % sz]].first - i, i});
}
map<long long, long long> mp;
for(int i = 0; i < sz + sz / 2; i++) {
if(i >= sz / 2) {
long long to_find = ans.first - (dp[cycle[i % sz]].first + i);
ans.second += mp[to_find] * dp[cycle[i % sz]].second;
mp[dp[cycle[i - sz / 2]].first - (i - sz / 2)] -= dp[cycle[i - sz / 2]].second;
}
mp[dp[cycle[i % sz]].first - i] += dp[cycle[i % sz]].second;
}
cout << ans.second << '\n';
}
int main() {
setIO();
auto solve = [&](int test_case)-> void {
while(test_case--) {
solve_();
}
};
int test_cases = 1;
// cin >> test_cases;
solve(test_cases);
return 0;
}
Compilation message
shymbulak.cpp: In function 'void setIO(std::string)':
shymbulak.cpp:67:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
67 | freopen((str + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
shymbulak.cpp:68:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
68 | freopen((str + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
shymbulak.cpp:72:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
72 | freopen("input.txt", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
shymbulak.cpp:73:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
73 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
4948 KB |
Output is correct |
| 2 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 3 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 4 |
Correct |
3 ms |
5028 KB |
Output is correct |
| 5 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 6 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 7 |
Correct |
3 ms |
5036 KB |
Output is correct |
| 8 |
Correct |
2 ms |
5032 KB |
Output is correct |
| 9 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 10 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 11 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 12 |
Correct |
3 ms |
5032 KB |
Output is correct |
| 13 |
Correct |
3 ms |
5028 KB |
Output is correct |
| 14 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 15 |
Correct |
3 ms |
5052 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
5160 KB |
Output is correct |
| 2 |
Correct |
3 ms |
5040 KB |
Output is correct |
| 3 |
Correct |
4 ms |
5164 KB |
Output is correct |
| 4 |
Correct |
3 ms |
5076 KB |
Output is correct |
| 5 |
Correct |
4 ms |
5332 KB |
Output is correct |
| 6 |
Correct |
4 ms |
5372 KB |
Output is correct |
| 7 |
Correct |
4 ms |
5360 KB |
Output is correct |
| 8 |
Correct |
4 ms |
5332 KB |
Output is correct |
| 9 |
Correct |
4 ms |
5332 KB |
Output is correct |
| 10 |
Correct |
4 ms |
5332 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
41 ms |
11092 KB |
Output is correct |
| 2 |
Correct |
44 ms |
11836 KB |
Output is correct |
| 3 |
Correct |
58 ms |
22172 KB |
Output is correct |
| 4 |
Correct |
31 ms |
11908 KB |
Output is correct |
| 5 |
Correct |
31 ms |
11764 KB |
Output is correct |
| 6 |
Correct |
104 ms |
17136 KB |
Output is correct |
| 7 |
Correct |
71 ms |
14632 KB |
Output is correct |
| 8 |
Correct |
60 ms |
18464 KB |
Output is correct |
| 9 |
Correct |
62 ms |
18060 KB |
Output is correct |
| 10 |
Correct |
67 ms |
20148 KB |
Output is correct |
| 11 |
Correct |
62 ms |
18476 KB |
Output is correct |
| 12 |
Correct |
71 ms |
19096 KB |
Output is correct |
