oj.uz

Submission #623490

# Submission time Handle Problem Language Result Execution time Memory
623490 2022-08-05T16:55:33 Z welleyth Capital City (JOI20_capital_city) C++17
1 / 100
 3000 ms 40812 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(2 * sz[to] >= n)
            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 <<s "\n";
    used[C] = true;
    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";
    }
    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 12908 KB Output is correct
3 Correct 7 ms 12884 KB Output is correct
4 Correct 11 ms 12824 KB Output is correct
5 Correct 9 ms 12884 KB Output is correct
6 Correct 9 ms 12908 KB Output is correct
7 Correct 10 ms 12908 KB Output is correct
8 Correct 8 ms 12884 KB Output is correct
9 Correct 8 ms 12884 KB Output is correct
10 Correct 8 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 12908 KB Output is correct
3 Correct 7 ms 12884 KB Output is correct
4 Correct 11 ms 12824 KB Output is correct
5 Correct 9 ms 12884 KB Output is correct
6 Correct 9 ms 12908 KB Output is correct
7 Correct 10 ms 12908 KB Output is correct
8 Correct 8 ms 12884 KB Output is correct
9 Correct 8 ms 12884 KB Output is correct
10 Correct 8 ms 12884 KB Output is correct
11 Correct 10 ms 13168 KB Output is correct
12 Correct 13 ms 13132 KB Output is correct
13 Correct 12 ms 13252 KB Output is correct
14 Correct 12 ms 13140 KB Output is correct
15 Correct 11 ms 13156 KB Output is correct
16 Correct 10 ms 13012 KB Output is correct
17 Incorrect 12 ms 13176 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 596 ms 35992 KB Output is correct
2 Correct 250 ms 36164 KB Output is correct
3 Correct 622 ms 35804 KB Output is correct
4 Correct 228 ms 36236 KB Output is correct
5 Correct 624 ms 36196 KB Output is correct
6 Correct 238 ms 36392 KB Output is correct
7 Correct 647 ms 37644 KB Output is correct
8 Correct 286 ms 40148 KB Output is correct
9 Execution timed out 3066 ms 40812 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 12908 KB Output is correct
3 Correct 7 ms 12884 KB Output is correct
4 Correct 11 ms 12824 KB Output is correct
5 Correct 9 ms 12884 KB Output is correct
6 Correct 9 ms 12908 KB Output is correct
7 Correct 10 ms 12908 KB Output is correct
8 Correct 8 ms 12884 KB Output is correct
9 Correct 8 ms 12884 KB Output is correct
10 Correct 8 ms 12884 KB Output is correct
11 Correct 10 ms 13168 KB Output is correct
12 Correct 13 ms 13132 KB Output is correct
13 Correct 12 ms 13252 KB Output is correct
14 Correct 12 ms 13140 KB Output is correct
15 Correct 11 ms 13156 KB Output is correct
16 Correct 10 ms 13012 KB Output is correct
17 Incorrect 12 ms 13176 KB Output isn't correct
18 Halted 0 ms 0 KB -