Submission #971795

#	Time	Username	Problem	Language	Result	Execution time	Memory
971795		vjudge1	Meetings 2 (JOI21_meetings2)	C++14	100 / 100	314 ms	27248 KiB

meetings2

#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll,ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 1e9+7;
const ll inf = 1e18;
const ll base = 26;
const ll blocksz = 100;
const ll N = 2e5+8;
const ll lim = 1e5+8;
ll sz[N],h[N],mx[N],nmx[N],ans[N],n;
vi g[N];
bool del[N];
void cc(ll u, ll p){
    sz[u] = 1;
    for(ll v:g[u]){
        if(v == p || del[v]) continue;
        cc(v,u);
        sz[u] += sz[v];
    }
}
ll centroid(ll u, ll p, ll siz){
    for(ll v:g[u]){
        if(v != p && !del[v] && sz[v] > siz/2){
            return centroid(v,u,siz);
        }
    }
    return u;
}
void dfs(ll u, ll p){
    sz[u] = 1;
    for(ll v:g[u]){
        if(v != p && !del[v]){
            h[v] = h[u]+1;
            dfs(v,u);
            sz[u] += sz[v];
        }
    }
    nmx[sz[u]] = max(nmx[sz[u]],h[u]);
}
void decompose(ll u){
    cc(u,u);
    ll c = centroid(u,u,sz[u]);
    h[c] = 1;
    ll reset = 0;
    for(ll v:g[c]){
        if(!del[v]){
            h[v] = h[c]+1;
            dfs(v,c);
            reset = max(reset,sz[v]);
            for(ll i = sz[v]; i >= 0; i--) nmx[i] = max(nmx[i],nmx[i+1]);
            for(ll i = sz[v]; i >= 0; i--){
                ans[i<<1] = max(ans[i<<1],max(1LL,mx[i])+nmx[i]-1);
            }
            for(ll i = sz[v]; i >= 0; i--){
                mx[i] = max(mx[i],nmx[i]);
                nmx[i] = 0;
            }
        }
    }
    for(ll i = 0; i <= reset; i++) mx[i] = 0;
    del[c] = 1;
    for(ll v:g[c]) if(!del[v]) decompose(v);
}
void solve(){
    cin >> n;
    for(ll i = 1; i < n; i++){
        ll u,v;cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    for(ll i = 1; i <= n; i++) ans[i] = 1;
    decompose(1);
    for(ll i = 1; i <= n; i++) cout << ans[i] << '\n';
}
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    if(fopen("test.inp","r")){
        freopen("test.inp","r",stdin);
        freopen("test.out","w",stdout);
    }
    int T = 1;
    // cin >> T;
    for(int tt = 1; tt <= T; tt++){
    	solve();
    	cout << '\n';
    }
}  

Compilation message (stderr)

meetings2.cpp: In function 'int main()':
meetings2.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen("test.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
meetings2.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen("test.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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