Submission #971523

#	Time	Username	Problem	Language	Result	Execution time	Memory
971523		_shr104	Meetings 2 (JOI21_meetings2)	C++14	100 / 100	325 ms	28360 KiB

meetings2

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pf push_front
#define fi first
#define se second
const ll mod = 1e9+7, mxn = 2e5+7;
ll sz[mxn], max_h[mxn], old_max_h[mxn], n, h[mxn], ans[mxn];
bool del[mxn];
vector<vector<ll>> g(mxn);
void dfs_sz(ll u, ll v) {sz[u] = 1; for (ll i : g[u]) {if (i != v && !del[i]) {dfs_sz(i,u); sz[u] += sz[i];}}}
ll dfs_ctr(ll u, ll v, ll szx) {for (ll i : g[u]) {if (i != v && !del[i] && sz[i] > szx/2) {return dfs_ctr(i,u,szx);}} return u;}
void dfs_mx(ll u, ll v)
{
    sz[u] = 1;
    for (ll i : g[u]) {if (i != v && !del[i]) {h[i] = h[u]+1; dfs_mx(i,u); sz[u] += sz[i];}}
    max_h[sz[u]] = max(max_h[sz[u]],h[u]);
}
void solve(ll u)
{
    dfs_sz(u,u); u = dfs_ctr(u,u,sz[u]); h[u] = 1; ll reset_bound = 0;
    for (ll i : g[u])
    {
        if (!del[i]) 
        {
            h[i] = 2; dfs_mx(i,u); reset_bound = max(reset_bound,sz[i]);
            for (ll j = sz[i]; j >= 0; j--) max_h[j] = max(max_h[j],max_h[j+1]);
            for (ll j = sz[i]; j >= 0; j--)
            {
                ans[j<<1] = max(ans[j<<1],max_h[j]+max(old_max_h[j],1LL)-1);
                old_max_h[j] = max(old_max_h[j],max_h[j]); max_h[j] = 0;
            }
        }   
    }
    for (ll i = reset_bound; i >= 0; i--) old_max_h[i] = max_h[i] = 0;
    del[u] = 1; for (ll i : g[u]) {if (!del[i]) {solve(i);}}
}
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
    cin >> n;
    for (ll i = 1; i < n; i++)
    {
        ll a, b; cin >> a >> b;
        g[a].pb(b); g[b].pb(a);
    }
    solve(1); for (ll i = 1; i <= n; i++) cout << max(ans[i],1LL) << '\n';
}

• Subtask 1: 4 / 4
• Subtask 2: 16 / 16
• Subtask 3: 80 / 80