Submission #1116869

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116869		vjudge1	Mergers (JOI19_mergers)	C++17	48 / 100	414 ms	262144 KiB

mergers

#include <bits/stdc++.h>
#define int long long int

using namespace std;

const int maxn = 1e5 + 100;

int n ,k, a[maxn], num[maxn], sz[maxn], cnt[maxn] ,ans;
bool mark[maxn];

vector<int> adj[maxn];
vector<int> states[maxn];

void dfs1(int v, int mpar = 0){
    sz[v] = 1;
    states[v][a[v]] = true;
    for(auto u : adj[v]){
        if(u != mpar){
            dfs1(u, v);
            sz[v] += sz[u];
            cnt[v] += cnt[u];
            for(int i = 1; i <= k; i++){
                states[v][i] |= states[u][i];
            }
        }
    }
    int tedad = 0;
    for(int i = 1; i <= k ;i ++){
        if(states[v][i]){
            tedad += num[i];
        }
    }
    if((v != 1) and (tedad == sz[v])){
        mark[v] = true;
        cnt[v]++;
    }
}


void dfs2(int v ,int mpar = 0){
    if(mark[v]){
        if(cnt[v] == 1 or cnt[v] == cnt[1]){
            ans++;
        }
    }
    for(auto u : adj[v]){
        if(u != mpar){
            dfs2(u ,v);
        }
    }
}


int32_t main(){

    ios::sync_with_stdio(0) ,cout.tie(0) ,cin.tie(0);

    cin >> n >> k;
    for(int i = 0 ;i < n - 1 ;i++){
        int x ,y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        num[a[i]]++;
    }

    for(int i = 1 ;i <= n; i++){
        states[i] = vector<int> (k + 100, 0);
    }

    dfs1(1), dfs2(1);

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

    system("pause");

    return 0;
}

Compilation message (stderr)

mergers.cpp: In function 'int32_t main()':
mergers.cpp:78:11: warning: ignoring return value of 'int system(const char*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |     system("pause");
      |     ~~~~~~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 24 / 24
• Subtask 3: 14 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30