oj.uz

Submission #331450

# Submission time Handle Problem Language Result Execution time Memory
331450 2020-11-28T14:07:18 Z neki Papričice (COCI20_papricice) C++14
0 / 110
 1 ms 364 KB 
#include <bits/stdc++.h>
#define loop(i, a, b) for(long long i=a;i<b;i++)
#define pool(i, a, b) for(long long i=a-1;i>=b;i--)
#define fore(i, a) for(auto&& i:a)
#define fi first
#define se second
#define ps(a) push_back(a)
#define pb(a) pop_back(a)
#define sc scanf
#define vc vector
#define pa pair<ll, ll>
#define ll long long
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define llmax LLONG_MAX/2
#define llmin -LLONG_MAX/2
using namespace std;
#define mn 310
#define pa pair<ll, ll>
#define ld long double 
vc<ll> edg[mn];
ll n, siz[mn];
void get(ll u, ll p){
    siz[u]=1;
    fore(v, edg[u]) if(v!=p){
        get(v, u);
        siz[u]+=siz[v];
    }
}

set<ll> alls, sub[mn];
ll raz(ll a, ll b, ll c){return max(a, max(b, c)) -  min(a, min(b, c));}

ll ans;
void dfs(ll u, ll p){
    auto z=alls.lower_bound((n-siz[u])/2);
    if(z!=alls.end()) ans=min(ans, raz(siz[u], (*z), n-(*z)));
    if(z!=alls.begin()){--z; ans=min(ans, raz(siz[u], (*z), n-(*z)));}
    fore(v, edg[u]) if(v!=p){
        dfs(v, u);
        if(sub[v].size()>sub[u].size()) swap(sub[v], sub[u]);
    }
    fore(v, edg[u]) if(v!=p){
        fore(el, sub[v]) sub[u].insert(el);
    }
    auto s=sub[u].lower_bound(siz[u]/2);
    /*if(s!=sub[u].end()){
        cout << n << " "<<siz[u]<< " "<<(*s)<<endl;
        cout<<n-siz[u]<<" " <<siz[u] -(*s)<<" "<< (*s)<< " "<<raz(n-siz[u], siz[u] -(*s), (*s))<<endl;
        
    }*/
    
    if(s!=sub[u].end()) ans=min(ans, raz(n-siz[u], siz[u] -(*s), (*s)));
    if(s!=sub[u].begin()){--s; ans=min(ans, raz(n-siz[u], siz[u] -(*s), (*s)));}
    sub[u].insert(siz[u]);
    alls.insert(siz[u]);
}

int main() {
    cin >> n;
    ans=raz(1, 1, n-2);
    loop(i, 0, n-1){
        ll a, b;cin >> a >> b;
        edg[a].ps(b);
        edg[b].ps(a);
    }
    get(1, -1);
    dfs(1, -1);
    cout << ans<<endl;
}

Subtask #1
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Incorrect 1 ms 364 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Incorrect 1 ms 364 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Incorrect 1 ms 364 KB Output isn't correct
4 Halted 0 ms 0 KB -