Submission #804375

#	Time	Username	Problem	Language	Result	Execution time	Memory
804375		vjudge1	Meetings 2 (JOI21_meetings2)	C++17	0 / 100	1 ms	1072 KiB

meetings2

#include <bits/stdc++.h>



using namespace std;

#define TL ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define rall(s) s.rbegin(),s.rend()
#define all(s) s.begin(),s.end()
#define pb push_back
#define fi first
#define se second
#define ll long long
#define ld long double
#define YES cout<<"YES\n"
#define Yes cout<<"Yes\n"
#define yes cout<<"yes\n"
#define NO cout<<"NO\n"
#define No cout<<"No\n"
#define no cout<<"no\n"


const int N = 1e4 + 9 , mod = 1e9 + 7;
ll  d[N] = {} , a[N] = {}, dp[N] = {}, b[N] , c[N] , us[N] = {} , us1[N] = {} , p[N][20] , sz[N] = {} , root , timer = 0;

vector<int>v[N] ;
set<ll>st[N];

bool is_upper(int x , int y){
    return (us[x] <= us[y] && us1[x] >= us1[y]);
}


ll lca(int x , int y){
    if(is_upper(x , y))
        return x;
    if(is_upper(y , x))
        return y;
    for(int i = 19; i >= 0; i--)
        if(p[x][i] && !is_upper(p[x][i] , y))
            x = p[x][i] ;
    return p[x][0];
}

ll dist(int x , int y){
    return (d[x] + d[y] - (2 * d[lca(x ,y)]));
}

void dfs(int n ){
    us[n] = ++timer;
    for(int i = 1; i < 20; i++)
        p[n][i] = p[p[n][i - 1]][i - 1];
    for(auto to : v[n])
        if(us[to] == 0)
            d[to] = d[n] + 1, p[to][0] = n , dfs(to);
    us1[n] = ++timer;
}


void solve(){
    ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
    cin>>n;
    for(i = 1; i < n; i++){
        cin>>l>>r;
        v[l].pb(r);
        v[r].pb(l);
        st[l].insert(r);
        st[r].insert(l);
    }
    for(i = 1; i <= n; i++)
        if(v[i].size() == 1)
            root = i;
    dfs(1);
    set<pair<int,int>> s1 , s2;
    for(i = 1; i <= n; i++){
        b[i] = 1;
        if(st[i].size() == 1)
            s1.insert({b[i] , i});
    }
    while(s1.size()){
        auto it = s1.begin();
        k = it->se;
        s2.insert({b[k] , k});
        s1.erase(it);
        if(st[k].size() == 1){
            x = *st[k].begin();
            s2.insert({b[k] , k});
            st[x].erase(k);
            st[k].erase(x);
            b[x] += b[k];
            s2.insert({b[x] , x});
            if(st[x].size() == 1)
                s1.insert({b[x] , x});
        }
    }
    for(i = n; i >= 1; i--){
        if(i % 2 == 1){
            c[i] = 1;
        }else {
            mx = 2;
            vector<int>v;
            while(s2.size() && s2.rbegin()->fi >= (i / 2))
                v.pb(s2.rbegin()->se) , s2.erase({s2.rbegin()->fi , s2.rbegin()->se});
            for(x= 0;x < v.size();x++)
                for(y = x + 1; y < v.size(); y++)
                    mx = max(mx , dist(v[x] , v[y]) + 1);
            c[i] = max(c[i + 2] , mx);
        }
    }
    for(i = 1; i <= n; i++)
        cout<<c[i]<<"\n";
}

int main(){

     TL;
     /*
     #ifndef ONLINE_JUDGE
     freopen("input.txt", "r", stdin);
     freopen("output.txt", "w", stdout);
     #endif*/
int t = 1;
//cin>>t;

while(t--)
     {
     solve();
     }

}
// Author : حسن

Compilation message (stderr)

meetings2.cpp: In function 'void solve()':
meetings2.cpp:106:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |             for(x= 0;x < v.size();x++)
      |                      ~~^~~~~~~~~~
meetings2.cpp:107:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  107 |                 for(y = x + 1; y < v.size(); y++)
      |                                ~~^~~~~~~~~~
meetings2.cpp:63:8: warning: unused variable 'q' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |        ^
meetings2.cpp:63:16: warning: unused variable 'j' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                ^
meetings2.cpp:63:20: warning: unused variable 'm' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                    ^
meetings2.cpp:63:26: warning: unused variable 'z' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                          ^
meetings2.cpp:63:29: warning: unused variable 's' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                             ^
meetings2.cpp:63:37: warning: unused variable 'f' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                                     ^
meetings2.cpp:63:62: warning: unused variable 'mn' [-Wunused-variable]
   63 |     ll q , i , j , m ,n, z ,s = 0 , f ,  l , r , k , x , y , mn  = 1e18 , mx = 0;
      |                                                              ^~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 16
• Subtask 3: 0 / 80