/*
VENI VIDI VICI
*/
// #pragma GCC optimize("Ofast","unroll-all-loops","fast-math","no-stack-protector","give-no-fuck")
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <algorithm>
// #include <set>
// #include <map>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define rep(i,x, n) for (int i = (x); i < (n); ++i)
#define repr(i,x, n) for (int i = (n) - 1; i >= (x); --i)
// #define sum accumulate
using i128 = __int128;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vi>;
template<class T>
istream& operator>>(istream& is, vector<T>& v) {
for(auto &i:v) is>>i;
return is;
}
template<class T1,class T2>
istream& operator>>(istream& is, pair<T1,T2>& p) {
is>>p.fi>>p.se;
return is;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
for(const auto &i:v) os<<i<<' ';
return os;
}
template<class T1,class T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p) {
os<<p.fi<<' '<<p.se; return os;
}
void pyn(bool x)
{
cout<<(x?"YES":"NO")<<endl;
}
void pYN(bool x)
{
cout<<(x?"Yes":"No")<<endl;
}
void pAB(bool x)
{
cout<<(x?"Alice":"Bob")<<endl;
}
ll powmod(ll a,ll b,ll modulo)
{
if(b==0){
return 1;
}
ll temp=powmod(a,b/2,modulo);
if(b%2==0){
return (temp*temp)%modulo;
}
else{
return (a*((temp*temp)%modulo))%modulo;
}
}
bool Prime(ll n){
for (ll i = 2; i*i <= n; i++)
if (n % i == 0)
return false;
return (n>1);
}
const ll N=3e5+100;
vl ma[N];
ll dp[N];
void dfs(int x,int p=-1,int vl=1)
{
dp[x]=vl-ma[x].size()+(p!=-1);
for(auto y:ma[x])
{
if(y==p)continue;
dfs(y,x,vl);
dp[x]+=min(dp[y],0ll);
}
}
bool check(ll x)
{
dfs(1,-1,x);
return dp[1]>=0;
}
void solve()
{
ll n;
cin>>n;
rep(i,1,n)
{
int x,y;
cin>>x>>y;
ma[x].pb(y);
ma[y].pb(x);
}
ll l=-1,r=n;
// zero can be answer
while(l+1<r)
{
ll mid=(l+r)/2;
if(check(mid))
{
r=mid;
}
else
{
l=mid;
}
}
cout<<r<<endl;
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int uwu=1;
// cin>>uwu;
while(uwu--) {
solve();
}
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |