oj.uz

Submission #623493

# Submission time Handle Problem Language Result Execution time Memory
623493 2022-08-05T17:00:25 Z welleyth Capital City (JOI20_capital_city) C++17
1 / 100
 3000 ms 41004 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;

#define int long long
#define mp make_pair
#define pb push_back

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")

constexpr int INF = (int)2e18;
constexpr int N = (int)2e5 + 111;
constexpr int md = (int)998244353;
constexpr int mdPower = (int)1e9+7 - 1;
constexpr double eps = 1e-7;

typedef __int128 _uint;
typedef long long ll;

mt19937_64 rnd(time(nullptr));

void add(int& a,int b){
    a += b; if(a >= md) a -= md;
}
void sub(int& a,int b){
    a -= b; while(a < 0) a += md;
}
void add(__int128& a,int b){
    a += b;
}
void sub(__int128& a,int b){
    a -= b;
}

int bpow(int a,int b){
    if(b == 0)
        return 1;
    if(b % 2 == 0){
        int t = bpow(a,b>>1);
        return 1ll*t*t%md;
    }
    return 1ll * a*bpow(a,b-1) % md;
}

int inv(int a){
    return bpow(a,md-2);
}

int fac[N],invfac[N];

void init(){
    fac[0] = 1;
    for(int i = 1; i < N; i++){
        fac[i] = (fac[i-1] * i) % md;
    }
    invfac[N-1] = inv(fac[N-1]);
    for(int i = N-2; i >= 0; i--){
        invfac[i] = (invfac[i+1] * (i+1))%md;
    }
    return;
}

//int C(int n,int k){
//    if(k > n)
//        return 0;
//    return fac[n] * invfac[k] % md * invfac[n-k] % md;
//}
//
//int A(int n,int k){
//    if(k > n)
//        return 0;
//    return fac[n] * invfac[n-k] % md;
//}

vector<int> g[N];
int col[N];
vector<int> cities[N];
int sz[N];
int ans = INF;
bool used[N];
bool choosen[N];
int p[N];
int L[N];
int d[N];

void dfs1(int v,int pr = -1){
    sz[v] = 1;
    for(auto& to : g[v]){
        if(to == pr || used[to])
            continue;
        dfs1(to,v);
        sz[v] += sz[to];
    }
    return;
}

int getCentroid(int v,int n,int pr = -1){
    for(auto& to : g[v]){
        if(to == pr || used[to])
            continue;
        if(sz[to] > (n+1)/2)
            return getCentroid(to,n,v);
    }
    return v;
}

int CNT = 0;
void dfs3(int v,int pr = -1){
    L[v] = CNT;
    for(auto& to : g[v]){
        if(to == pr || used[to])
            continue;
        p[to] = v;
        d[to] = d[v] + 1;
        dfs3(to,v);
    }
    return;
}

void solve(int v,int pr = -1){
    dfs1(v);
    int C = getCentroid(v,sz[v]);
//    cerr << "C = " << C << "\n";
    int cur_col = col[C];
    dfs1(C);
    CNT++;
    d[C] = 0;
    dfs3(C);
//    cerr << "ok\n";
    if(!choosen[cur_col]){
        set<int> added_colors;
        added_colors.insert(cur_col);
        set<pair<int,int>> q;
        bool ok = true;
        set<int> visited;
        for(auto& x : cities[cur_col]){
            q.insert(mp(-d[x],x));
            visited.insert(x);
            if(L[x] != CNT){
                ok = false;
                break;
            }
        }
        while(!q.empty() && ok){
            int v = q.begin()->second;
            q.erase(q.begin());
//            cerr << "v = " << v << "\n";
            if(choosen[col[v]]){
                ok = false;
                break;
            }
            if(!added_colors.count(col[v])){
                for(auto& x : cities[col[v]]){
                    if(!visited.count(x)){
                        q.insert(mp(-d[x],x));
                        visited.insert(x);
                    }
                    if(L[x] != CNT){
                        ok = false;
                    }
                }
                added_colors.insert(col[v]);
            }
            if(p[v] > 0 && !visited.count(p[v])){
                q.insert(mp(-d[p[v]],p[v]));
                visited.insert(p[v]);
            }
        }
        if(ok){
            ans = min(ans,(int)added_colors.size()-1);
            choosen[cur_col] = 1;
        }
//        cerr << "v = " << v << ", centroid = " << C << "\n";
    }
    used[C] = true;
    for(auto& to : g[C]){
        if(!used[to]){
            solve(to);
        }
    }
    return;
}

void solve(){
    int n,k;
    cin >> n >> k;

    for(int i = 1; i < n; i++){
        int a,b;
        cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }

    for(int i = 1; i <= n; i++){
        cin >> col[i];
        cities[col[i]].pb(i);
    }

    solve(1);

    assert(ans != INF);
    cout << ans << "\n";

    return;
}

signed main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
    init();
    int tests = 1;
//    cin >> tests;
    for(int test = 1; test <= tests; test++){
//        cerr << "test = " << test << "\n";
        solve();
    }
    return 0;
}
/**

**/

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12884 KB Output is correct
2 Correct 8 ms 12884 KB Output is correct
3 Correct 8 ms 12860 KB Output is correct
4 Correct 8 ms 12884 KB Output is correct
5 Correct 8 ms 12884 KB Output is correct
6 Correct 8 ms 12884 KB Output is correct
7 Correct 8 ms 12856 KB Output is correct
8 Correct 9 ms 12884 KB Output is correct
9 Correct 10 ms 12884 KB Output is correct
10 Correct 9 ms 12884 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12884 KB Output is correct
2 Correct 8 ms 12884 KB Output is correct
3 Correct 8 ms 12860 KB Output is correct
4 Correct 8 ms 12884 KB Output is correct
5 Correct 8 ms 12884 KB Output is correct
6 Correct 8 ms 12884 KB Output is correct
7 Correct 8 ms 12856 KB Output is correct
8 Correct 9 ms 12884 KB Output is correct
9 Correct 10 ms 12884 KB Output is correct
10 Correct 9 ms 12884 KB Output is correct
11 Correct 11 ms 13184 KB Output is correct
12 Correct 10 ms 13140 KB Output is correct
13 Correct 11 ms 13252 KB Output is correct
14 Correct 11 ms 13140 KB Output is correct
15 Correct 11 ms 13048 KB Output is correct
16 Correct 10 ms 13120 KB Output is correct
17 Incorrect 10 ms 13140 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 683 ms 36004 KB Output is correct
2 Correct 244 ms 36268 KB Output is correct
3 Correct 616 ms 35872 KB Output is correct
4 Correct 236 ms 36088 KB Output is correct
5 Correct 643 ms 36400 KB Output is correct
6 Correct 236 ms 36396 KB Output is correct
7 Correct 699 ms 37688 KB Output is correct
8 Correct 299 ms 40080 KB Output is correct
9 Execution timed out 3079 ms 41004 KB Time limit exceeded
10 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12884 KB Output is correct
2 Correct 8 ms 12884 KB Output is correct
3 Correct 8 ms 12860 KB Output is correct
4 Correct 8 ms 12884 KB Output is correct
5 Correct 8 ms 12884 KB Output is correct
6 Correct 8 ms 12884 KB Output is correct
7 Correct 8 ms 12856 KB Output is correct
8 Correct 9 ms 12884 KB Output is correct
9 Correct 10 ms 12884 KB Output is correct
10 Correct 9 ms 12884 KB Output is correct
11 Correct 11 ms 13184 KB Output is correct
12 Correct 10 ms 13140 KB Output is correct
13 Correct 11 ms 13252 KB Output is correct
14 Correct 11 ms 13140 KB Output is correct
15 Correct 11 ms 13048 KB Output is correct
16 Correct 10 ms 13120 KB Output is correct
17 Incorrect 10 ms 13140 KB Output isn't correct
18 Halted 0 ms 0 KB -