Submission #1137018

#	Time	Username	Problem	Language	Result	Execution time	Memory
1137018		steveonalex	Meetings 2 (JOI21_meetings2)	C++20	100 / 100	401 ms	29252 KiB

meetings2

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2e5 + 69;
int n;
vector<pair<int, int>> graph[N];
int ans[N];

namespace CD{
    const int INF = 1e9 + 69;

    struct FenwickTree{
        int n;
        vector<int> a;
    
        FenwickTree(int _n){
            n = _n;
            a.resize(n+1, -INF);
        }
    
        void update(int i, ll v){
            i = n - i + 1;
            while(i <= n){
                maximize(a[i], v);
                i += LASTBIT(i);
            }
        }
    
        int get(int i){
            i = n - i + 1;
            int ans = 0;
            while(i > 0){
                maximize(ans, a[i]);
                i -= LASTBIT(i);
            }
            return ans;
        }
    };
    
    int sz[N];
    bool banned[N];
    void find_sz(int u, int p){
        sz[u] = 1;
        for(pair<int, int> v: graph[u]) if (v.first != p && !banned[v.second]){
            find_sz(v.first, u);
            sz[u] += sz[v.first];
        }
    }

    int find_centroid(int u){
        for(pair<int, int> v: graph[u]) if (!banned[v.second] && sz[v.first] > sz[u] / 2){
            sz[u] -= sz[v.first];
            sz[v.first] += sz[u];

            return find_centroid(v.first);
        }
        return u;
    }

    void go(int u, int p, int h, vector<pair<int,int>> &li){
        li.push_back({h, sz[u]});
        for(pair<int, int> v: graph[u]) if (!banned[v.second] && v.first != p){
            go(v.first, u, h + 1, li);
        }
    }

    void go(int u){
        find_sz(u, 0);
        u = find_centroid(u);

        int cur_sz = sz[u];

        vector<vector<pair<int, int>>> child;
        for(pair<int, int> v: graph[u]) if (!banned[v.second]){
            child.emplace_back();
            go(v.first, u, 1, child.back());
        }

        FenwickTree bit(cur_sz);
        for(auto i: child){
            int peak = i[0].second;
            for(pair<int, int> j: i){
                maximize(ans[min(j.second, cur_sz - peak) * 2], j.first + 1);
                int ma = bit.get(j.second);
                maximize(ans[j.second * 2], j.first + ma + 1);
            }
            for(pair<int, int> j: i){
                bit.update(j.second, j.first);
            }
        }
        reverse(ALL(child));
        bit = FenwickTree(cur_sz);
        for(auto i: child){
            for(pair<int, int> j: i){
                int ma = bit.get(j.second);
                maximize(ans[j.second * 2], j.first + ma + 1);
            }
            for(pair<int, int> j: i){
                bit.update(j.second, j.first);
            }
        }

        for(pair<int, int> v: graph[u]) if (!banned[v.second]){
            banned[v.second] = true;
            go(v.first);
        }
    }
}

void solve(){   
    cin >> n;
    for(int i = 1; i < n; ++i){
        int u, v; cin >> u >> v;
        graph[u].push_back({v, i});
        graph[v].push_back({u, i});
    }

    CD::go(1);

    for(int i = 1; i <= n; ++i) maximize(ans[i], 1);
    for(int i = n-1; i >= 1; --i) maximize(ans[i], ans[i+1]);
    for(int i = 1; i <= n; i += 2) ans[i] = 1;

    for(int i = 1; i <= n; ++i) cout << ans[i] << " ";
    cout << "\n";
}

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);

    clock_t start = clock();

    solve();

    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

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