Submission #895049

#	Time	Username	Problem	Language	Result	Execution time	Memory
895049		Mohammadamin__Sh	Mergers (JOI19_mergers)	C++17	100 / 100	777 ms	170044 KiB

mergers

//In His Name
#include <bits/stdc++.h>
//#pragma GCC optimization("O3")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx2")
using namespace std;
#define ll long long
#define int ll
typedef pair<int, int> pii;
#define F first
#define S second
#define pb push_back
#define bug(x) cout << "Ah shit , here we go again : " << x <<endl
#define all(x) x.begin() , x.end()
const int maxn = 5e5 + 10, MOD = 1e9 + 7;
const ll INF = 1e18;
 
int n , k , state[maxn] , a[maxn] , ans , ok[maxn];
vector<int> adj[maxn];
map<int,int> gooni[maxn];
 
void Dfs(int v , int p){
    for(int u : adj[v]) {
        if (u == p) continue;
        Dfs(u, v);
        if (gooni[v].size() < gooni[u].size()) swap(gooni[v], gooni[u]) , swap(ok[v] , ok[u]);
    }
    for(int u : adj[v]){
        if(u == p) continue;
        ok[v] += ok[u];
        for(auto i : gooni[u]){
            gooni[v][i.F] += i.S;
            if(gooni[v][i.F] == state[i.F]) gooni[v].erase(i.F);
        }
    }
    gooni[v][a[v]]++;
    if(gooni[v][a[v]] == state[a[v]]) gooni[v].erase(a[v]);
    if(gooni[v].size() == 0 and v != 1){
        if(!ok[v]) ans ++;
        ok[v] = 1;
    }
}
 
int32_t main(){
    ios_base::sync_with_stdio(false);
 
    cin >> n >> k;
    for(int i = 1 ; i < n ; i++){
        int u , v;
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    for(int i = 1 ; i <= n ; i++){
        cin >> a[i];
        state[a[i]]++;
    }
    Dfs(1 , 0);
    if(n == 1) return cout << 0 , 0;
    if(ok[1] == 1) ans++;
    cout << (ans+1)/2 << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 24 / 24
• Subtask 3: 14 / 14
• Subtask 4: 22 / 22
• Subtask 5: 30 / 30