oj.uz

답안 #439132

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
439132 2021-06-29T09:19:00 Z 2548631 Papričice (COCI20_papricice) C++17
110 / 110
 324 ms 21664 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef complex<ld> cp;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vii;
typedef vector<cp> vcp;
typedef vector<ld> vld;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vii> vvii;

#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define forw(i,l,r) for( int i = (l) ; i < (r) ; i++ )
#define forb(i,r,l) for( int i = (r) ; i >= (l) ; i-- )
#define log2i(x) (64 - __builtin_clzll(1ll*(x)) - 1)
#define numBit(x) (__builtin_popcountll(1ll*(x)))
#define getBit(x,i) ((x)>>(i)&1)
#define Pi acos(-1.0l)
#define sz(x) int(x.size())
#define mt make_tuple
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define debug(x) cerr << #x << " = " << x << '\n';

const int N = 2e5+7;
int n,ans=N;
int cnt[N];
vi edge[N];
set<int> sA,sB;

void pre_dfs(int u, int par=-1) {
    cnt[u]=1;
    for(auto v:edge[u]) if(v!=par) {
        pre_dfs(v,u);
        cnt[u]+=cnt[v];
    }
}

void upd(int x, int y, int z) {
    ans=min(ans,max({x,y,z})-min({x,y,z}));
}

void process(int u) {
    auto it=sA.upper_bound((n+cnt[u])/2);
    if(it!=sA.end()) upd(cnt[u],n-*it,*it-cnt[u]);
    if(it!=sA.begin()) {
        it--;
        upd(cnt[u],n-*it,*it-cnt[u]);
    }
    it=sB.upper_bound((n-cnt[u])/2);
    if(it!=sB.end()) upd(cnt[u],n-*it-cnt[u],*it);
    if(it!=sB.begin()) {
        it--;
        upd(cnt[u],n-*it-cnt[u],*it);
    }
}

void dfs(int u, int par=-1) {
    process(u);
    sA.insert(cnt[u]);
    for(auto v:edge[u]) if(v!=par) dfs(v,u);
    sA.erase(cnt[u]);
    sB.insert(cnt[u]);
}

int main() {
    fastIO;
#ifndef ONLINE_JUDGE
    //freopen("test.inp","r",stdin);
    //freopen("test.out","w",stdout);
#endif // ONLINE_JUDGE

    cin >> n;
    forw(i,1,n) {
        int u,v; cin >> u >> v;
        u--, v--;
        edge[u].pb(v);
        edge[v].pb(u);
    }
    pre_dfs(0);
    dfs(0);
    cout << ans << '\n';
    return 0;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 5 ms 5068 KB Output is correct
7 Correct 5 ms 5196 KB Output is correct
8 Correct 5 ms 5068 KB Output is correct
9 Correct 5 ms 5068 KB Output is correct
10 Correct 4 ms 5032 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 5 ms 5068 KB Output is correct
7 Correct 5 ms 5196 KB Output is correct
8 Correct 5 ms 5068 KB Output is correct
9 Correct 5 ms 5068 KB Output is correct
10 Correct 4 ms 5032 KB Output is correct
11 Correct 300 ms 14716 KB Output is correct
12 Correct 324 ms 14640 KB Output is correct
13 Correct 260 ms 15004 KB Output is correct
14 Correct 249 ms 15012 KB Output is correct
15 Correct 255 ms 14592 KB Output is correct
16 Correct 159 ms 14600 KB Output is correct
17 Correct 274 ms 14728 KB Output is correct
18 Correct 248 ms 21664 KB Output is correct
19 Correct 272 ms 14756 KB Output is correct
20 Correct 221 ms 14736 KB Output is correct