제출 #667469

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
667469		Soul234	Mergers (JOI19_mergers)	C++14	0 / 100	65 ms	34480 KiB

mergers

#include<bits/stdc++.h>
using namespace std;

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
#define fi first
#define se second

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
using db = long double;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

tcT> bool ckmin(T&a, const T&b) {
    return b < a ? a=b,1 : 0; }
tcT> bool ckmax(T&a, const T&b) {
    return b > a ? a=b,1 : 0; }

const int MOD = 1e9 + 7;
const ll INF = 1e18;

const int MX = 5e5+5;

int N, K;
int col[MX];

bool ok[MX];

vi lst[MX];

int cc = 0;

int ccid[MX];

vi adj[MX];

void dfs(int u, int p, int req) {
    ccid[u] = cc;
    each(v, adj[u]) if(v != p && !ccid[v] && col[v] == req) {
        dfs(v, u, req);
    }
}

int deg[MX];
pi eds[MX];
int cnt[MX];

void solve() {
    cin >> N >> K;
    F0R(i, N-1) {
        int u, v;
        cin >> u >> v;
        eds[i] = {u, v};
        adj[u].pb(v);
        adj[v].pb(u);
    }
    FOR(i,1,N+1) {
        cin >> col[i];
        lst[col[i]].pb(i);
    }
    if(K == 1) {
        cout << "0\n";
        return;
    }
    FOR(i,1,K+1) {
        each(u, lst[i]) if(!ccid[u]) {
            cc++;
            cnt[i]++;
            dfs(u, -1, i);
        }
    }

    F0R(i, N-1) {
        int u = eds[i].fi, v = eds[i].se;
        u = ccid[u], v = ccid[v];
        if(u != v) {
            deg[u]++;
            deg[v]++;
        }
    }

    int ans = 0;

    FOR(i,1,K+1) if(cnt[i] == 1 && deg[ccid[lst[i][0]]] == 1) {
        ans++;
    }

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

int main() {
    setIO();

    int t=1;
    //cin>>t;
    while(t-->0) {
        solve();
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

mergers.cpp: In function 'void setIO(std::string)':
mergers.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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