oj.uz

답안 #944355

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
944355 2024-03-12T15:33:52 Z VinhLuu Mergers (JOI19_mergers) C++17
0 / 100
 60 ms 54772 KB 
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(lmao) lmao.begin(), lmao.end()

using namespace std;

typedef pair<int,int> pii;
typedef tuple<int,int,int> tp;
const int N = 5e5 + 5;
const ll oo = 1e16;
const int mod = 1e9 + 7;
const int base = 23;

int n, k, X[N], Y[N], col[N], a[N], f[N], dp[N], in[N], en[N], demin, b[N];
vector<int> p[N], g[N], vr[N], m;
bool fl[N];

void pre(int u,int v){
    dp[u] = ((int)p[u].size() == 1);
    in[u] = ++demin;
    b[demin] = u;
    for(auto j : p[u]){
        if(j == v) continue;
        pre(j, u);
        f[u] += f[j];
        dp[u] += dp[j];
    }
    en[u] = demin;
}

void dfs(int u,int v){
    if(dp[u] == f[u] && v != 0){
        m.pb(u);
        return;
    }
    for(auto j : p[u]){
        if(j == v) continue;
        dfs(j, u);
    }
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    #define task "v"
    if(fopen(task ".inp","r")){
        freopen(task ".inp","r",stdin);
        freopen(task ".out","w",stdout);
    }

    cin >> n >> k;

    for(int i = 1; i <= n - 1; i ++){
        cin >> X[i] >> Y[i];
        p[X[i]].pb(Y[i]);
        p[Y[i]].pb(X[i]);
    }
    int root = 1;
    for(int i = 1; i <= n; i ++){
        if((int)p[i].size() >= 2) root = i;
        int x; cin >> x;
        vr[x].pb(i);
        col[i] = x;
    }
    for(int i = 1; i < n; i ++){
        if(col[X[i]] == col[Y[i]]){
            g[X[i]].pb(Y[i]);
            g[Y[i]].pb(X[i]);
        }
    }
    if(n == 1){
        cout << 0;
        return 0;
    }
    if(n == 2){
        if(col[1] == col[2]){
            cout << 0 << "\n";
        }else cout << 1 << "\n";
        return 0;
    }
    in[n + 1] = n + 1;
    pre(root, 0);
    int ans = 0;
    for(int i = 1; i <= k; i ++){
        if(vr[i].empty()) continue;
        queue<int> q;
        q.push(vr[i][0]);
        fl[vr[i][0]] = true;
        while(!q.empty()){
            int u = q.front();
            q.pop();
            for(auto j : g[u]){
                if(fl[j]) continue;
                fl[j] = true;
                q.push(j);
            }
        }
        bool ff = true;
        int mi = n + 1;
        for(auto j : vr[i]){
            if(!fl[j]){
                ff = false;
            }
            if(in[j] < in[mi]) mi = j;
        }
        if(!ff) continue;
        int cnt = 0;
        for(auto j : vr[i]) if((int)p[j].size() == 1) cnt++;
        if(cnt != dp[mi]) continue;
        ans++;
    }

   cout << (ans + 1) / 2;
}

Compilation message

mergers.cpp: In function 'int main()':
mergers.cpp:54:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         freopen(task ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:55:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen(task ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 45400 KB Output is correct
2 Incorrect 9 ms 45404 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 45400 KB Output is correct
2 Incorrect 9 ms 45404 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 45400 KB Output is correct
2 Incorrect 9 ms 45404 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 50312 KB Output is correct
2 Correct 60 ms 54772 KB Output is correct
3 Incorrect 12 ms 45912 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 45400 KB Output is correct
2 Incorrect 9 ms 45404 KB Output isn't correct
3 Halted 0 ms 0 KB -