//Original Code:
//#include <self/utility>
//#include <self/debug>
//using namespace std;
//int n;
//vector<int> edges[200005];
//int sz[200005];
//vector<int> v1,v2;
//
//void calc(int x,int par,vector<int> &v)
//{
// v.push_back(sz[x]);
// for(auto u:edges[x])
// {
// if(u==par) continue;
// calc(u,x,v);
// }
//}
//
//pii go(int x,int par)
//{
// pii o=mp(n-sz[x],x);
// pii res=mp(inf,-1);
// for(auto u:edges[x])
// {
// if(u==par) continue;
// chmax(o.first,sz[u]);
// chmin(res,go(u,x));
// }
// chmin(res,o);
// return res;
//}
//
//void dfs(int x,int par)
//{
// sz[x]=1;
// for(auto u:edges[x])
// {
// if(u==par) continue;
// dfs(u,x);
// sz[x]+=sz[u];
// }
//}
//
//int calc(int a,int b,int c)
//{
// return max({a,b,c})-min({a,b,c});
//}
//
//int main()
//{
// // freopen("input.txt","r",stdin);
// cin>>n;
// for(int i=0;i<n-1;i++)
// {
// int x,y;
// scanf("%d%d",&x,&y);
// x--;
// y--;
// edges[x].emplace_back(y);
// edges[y].emplace_back(x);
// }
// dfs(0,-1);
// int rt=go(0,-1).second;
// dfs(rt,-1);
// sort(all(edges[rt]),[](int x,int y){return sz[x]>sz[y];});
// calc(edges[rt][0],rt,v1);
// calc(edges[rt][1],rt,v2);
// sort(all(v2));
// int res=inf;
// for(int x:v1)
// {
// int m=n-x;
// auto it=lower_bound(all(v2),m/2);
// if(it!=v2.end()) chmin(res,calc(x,*it,m-*it));
// if(it!=v2.begin()) chmin(res,calc(x,*prev(it),m-*prev(it)));
// }
// cout<<res<<endl;
// return 0;
//}
//substituted with C++ Inliner
#ifndef _SELF_UTILITY
#define _SELF_UTILITY 1
#include <numeric>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <string.h>
#include <stack>
#include <assert.h>
#include <bitset>
#include <time.h>
#define Endl endl
#define mp make_pair
#define mt make_tuple
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define over(A) {cout<<A<<endl;exit(0);}
#define all(A) A.begin(),A.end()
#define quickcin ios_base::sync_with_stdio(false);
#ifdef __TAKE_MOD
int mod;
#else
#ifdef __TAKE_CONST_MOD
const int mod=__TAKE_CONST_MOD;
#else
const int mod=1000000007;
#endif
#endif
const int gmod=3;
const int inf=1039074182;
#ifdef __TAKE_CONST_EPS
const double eps=__TAKE_CONST_EPS;
#else
const double eps=1e-9;
#endif
const double pi=3.141592653589793238462643383279;
const ll llinf=2LL*inf*inf;
template <typename T1,typename T2> inline void chmin(T1 &x,T2 b) {if(b<x) x=b;}
template <typename T1,typename T2> inline void chmax(T1 &x,T2 b) {if(b>x) x=b;}
inline void chadd(int &x,int b) {x+=b-mod;x+=(x>>31 & mod);}
template <typename T1,typename T2> inline void chadd(T1 &x,T2 b) {x+=b;if(x>=mod) x-=mod;}
template <typename T1,typename T2> inline void chmul(T1 &x,T2 b) {x=1LL*x*b%mod;}
template <typename T1,typename T2> inline void chmod(T1 &x,T2 b) {x%=b,x+=b;if(x>=b) x-=b;}
template <typename T> inline T mabs(T x) {return (x<0?-x:x);}
using namespace std;
#endif
#ifndef _SELF_DEBUG
#define _SELF_DEBUG 1
#ifndef _SELF_OPERATOR
#define _SELF_OPERATOR 1
using namespace std;
template <typename T>
ostream & operator<<(ostream &cout, const vector<T> &vec)
{
cout << "{";
for (int i = 0; i < (int)vec.size(); i++)
{
cout << vec[i];
if (i != (int)vec.size() - 1)
cout << ',';
}
cout << "}";
return cout;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &cout, pair<T1, T2> p)
{
cout << "(" << p.first << ',' << p.second << ")";
return cout;
}
template <typename T, typename T2>
ostream &operator<<(ostream &cout, set<T, T2> s)
{
vector<T> t;
for (auto x : s)
t.push_back(x);
cout << t;
return cout;
}
template <typename T, typename T2>
ostream &operator<<(ostream &cout, multiset<T, T2> s)
{
vector<T> t;
for (auto x : s)
t.push_back(x);
cout << t;
return cout;
}
template <typename T>
ostream &operator<<(ostream &cout, queue<T> q)
{
vector<T> t;
while (q.size())
{
t.push_back(q.front());
q.pop();
}
cout << t;
return cout;
}
template <typename T1, typename T2, typename T3>
ostream &operator<<(ostream &cout, map<T1, T2, T3> m)
{
for (auto &x : m)
{
cout << "Key: " << x.first << ' ' << "Value: " << x.second << endl;
}
return cout;
}
template <typename T1, typename T2>
void operator+=(pair<T1, T2> &x,const pair<T1, T2> y)
{
x.first += y.first;
x.second += y.second;
}
template <typename T1,typename T2>
pair<T1,T2> operator + (const pair<T1,T2> &x,const pair<T1,T2> &y)
{
return make_pair(x.first+y.first,x.second+y.second);
}
template <typename T1,typename T2>
pair<T1,T2> operator - (const pair<T1,T2> &x,const pair<T1,T2> &y)
{
return mp(x.first-y.first,x.second-y.second);
}
template <typename T1, typename T2>
pair<T1, T2> operator-(pair<T1, T2> x)
{
return make_pair(-x.first, -x.second);
}
template <typename T>
vector<vector<T>> operator~(vector<vector<T>> vec)
{
vector<vector<T>> v;
int n = vec.size(), m = vec[0].size();
v.resize(m);
for (int i = 0; i < m; i++)
{
v[i].resize(n);
}
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
v[i][j] = vec[j][i];
}
}
return v;
}
#endif
#include <sstream>
void print0x(int x)
{
std::vector <int> vec;
while(x)
{
vec.push_back(x&1);
x>>=1;
}
std::reverse(vec.begin(),vec.end());
for(int i=0;i<(int)vec.size();i++)
{
std::cout<<vec[i];
}
std::cout<<' ';
}
template <typename T>
void print0x(T x,int len)
{
std::vector <int> vec;
while(x)
{
std::cout<<(x&1);
x>>=1;
len--;
// vec.push_back(x&1);
// x>>=1;
}
while(len--) cout<<0;
// reverse(vec.begin(),vec.end());
// for(int i=(int)vec.size();i<len;i++)
// {
// putchar('0');
// }
// for(size_t i=0;i<vec.size();i++)
// {
// std::cout<<vec[i];
// }
// std::cout<<' ';
}
vector<string> vec_splitter(string s) {
s += ',';
vector<string> res;
while(!s.empty()) {
res.push_back(s.substr(0, s.find(',')));
s = s.substr(s.find(',') + 1);
}
return res;
}
void debug_out(
vector<string> __attribute__ ((unused)) args,
__attribute__ ((unused)) int idx,
__attribute__ ((unused)) int LINE_NUM) { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
if(idx > 0) cerr << ", "; else cerr << "Line(" << LINE_NUM << ") ";
stringstream ss; ss << H;
cerr << args[idx] << " = " << ss.str();
debug_out(args, idx + 1, LINE_NUM, T...);
}
#define debug(...) debug_out(vec_splitter(#__VA_ARGS__), 0, __LINE__, __VA_ARGS__)
#endif
using namespace std;
int n;
vector<int> edges[200005];
int sz[200005];
vector<int> v1,v2;
void calc(int x,int par,vector<int> &v)
{
v.push_back(sz[x]);
for(auto u:edges[x])
{
if(u==par) continue;
calc(u,x,v);
}
}
pii go(int x,int par)
{
pii o=mp(n-sz[x],x);
pii res=mp(inf,-1);
for(auto u:edges[x])
{
if(u==par) continue;
chmax(o.first,sz[u]);
chmin(res,go(u,x));
}
chmin(res,o);
return res;
}
void dfs(int x,int par)
{
sz[x]=1;
for(auto u:edges[x])
{
if(u==par) continue;
dfs(u,x);
sz[x]+=sz[u];
}
}
int calc(int a,int b,int c)
{
return max({a,b,c})-min({a,b,c});
}
int main()
{
// // freopen("input.txt","r",stdin);
cin>>n;
for(int i=0;i<n-1;i++)
{
int x,y;
scanf("%d%d",&x,&y);
x--;
y--;
edges[x].emplace_back(y);
edges[y].emplace_back(x);
}
dfs(0,-1);
int rt=go(0,-1).second;
dfs(rt,-1);
sort(all(edges[rt]),[](int x,int y){return sz[x]>sz[y];});
calc(edges[rt][0],rt,v1);
calc(edges[rt][1],rt,v2);
sort(all(v2));
int res=inf;
for(int x:v1)
{
int m=n-x;
auto it=lower_bound(all(v2),m/2);
if(it!=v2.end()) chmin(res,calc(x,*it,m-*it));
if(it!=v2.begin()) chmin(res,calc(x,*prev(it),m-*prev(it)));
}
cout<<res<<endl;
return 0;
}
Compilation message
papricice.cpp: In function 'int main()':
papricice.cpp:366:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
366 | scanf("%d%d",&x,&y);
| ~~~~~^~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 2 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 3 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 4 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 5 |
Correct |
3 ms |
4940 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 2 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 3 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 4 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 5 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 6 |
Incorrect |
4 ms |
5068 KB |
Output isn't correct |
| 7 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 2 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 3 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 4 |
Correct |
4 ms |
4940 KB |
Output is correct |
| 5 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 6 |
Incorrect |
4 ms |
5068 KB |
Output isn't correct |
| 7 |
Halted |
0 ms |
0 KB |
- |
