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답안 #376850

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
376850 2021-03-12T05:32:32 Z Kevin_Zhang_TW Mergers (JOI19_mergers) C++17
0 / 100
 277 ms 41188 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long ;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l) == r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 500010, MAX_K = 20;

int n, k, belong[MAX_N];
vector<int> edge[MAX_N];
vector<int> state[MAX_N];
ll sum[MAX_N];

int anc[MAX_K][MAX_N], in[MAX_N], out[MAX_N];
bool isanc(int a, int b) { return in[a] <= in[b] && out[a] >= out[b]; }
void dfs(int x, int lst = 1) {
	static int t;
	anc[0][x] = lst;
	in[x] = ++t;
	for (int u : edge[x]) if (u != lst)
		dfs(u, x);
	out[x] = t;
}

void dfs2(int x, int lst = -1) {
	for (int u : edge[x]) if (u != lst) {
		dfs2(u, x);
		sum[x] += sum[u];
	}
}


vector<int> vir;
void dfs3(int x, int lst = -1) {
	for (int u : edge[x]) if (u != lst)
		dfs3(u, x);

	int son = 0;
	for (int u : edge[x]) if (u != lst)
		if (sum[u] == 0) ++son;

	if (sum[x] == 0 && lst != -1) ++son;

	if (son) vir.pb(x);
}
int getlca(int a, int b) {
	for (int d = MAX_K-1;d >= 0;--d)
		if (!isanc(anc[d][a], b))
			a = anc[d][a];
	return isanc(a, b) ? a : anc[0][a];
}

int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> k;
	for (int a, b, i = 1;i < n;++i) {
		cin >> a >> b;
		edge[a].pb(b), edge[b].pb(a);
	}
	for (int i = 1;i <= n;++i) {
		cin >> belong[i];
		state[ belong[i] ].pb(i);
	}
	int rt = 1;
	while (edge[rt].size() > 1) ++rt;

	if (k == 1) return cout << 0 << '\n', 0;


	dfs(rt);
	for (int d = 1;d < MAX_K;++d)
		for (int i = 1;i <= n;++i)
			anc[d][i] = anc[d-1][ anc[d-1][i] ];

	for (int i = 1;i <= k;++i) {
		if (state[i].size() > 1) {
			sort(AI(state[i]), [&](int a, int b) {
					return in[a] < in[b];
					});
			for (int x : state[i])
				++sum[x];
			sum[ getlca(state[i][0], state[i].back()) ] -= state[i].size();
		}
	}

	dfs2(rt);

	dfs3(rt);

	sort(AI(vir), [&](int a, int b) {
			return in[a] < in[b]; });

	debug(AI(vir));

	vector<int> all;
	for (int i = 0;i < vir.size();++i) {
		all.pb(vir[i]);
		if (i+1 < vir.size())
			all.pb(getlca(vir[i], vir[i+1]));
   	}

	sort(AI(all), [&](int a, int b) {
			return in[a] < in[b]; });

	all.erase(unique(AI(all)), end(all));

	debug(AI(all));



	vector<int> stk;

	vector<int> cnt(n + 10);

	for (int u : all) {
		while (stk.size()) {
			int x = stk.back();
			DE(x, u);
			if (isanc(x, u)) break;
			stk.pop_back();
		}
		if (stk.size()) {
			int x = stk.back();
			DE(x, u);
			++cnt[x], ++cnt[u];
		}
		stk.pb(u);
	}

	int res = 0;

	for (int u : all)
		res += cnt[u] == 1;

	res = (res+1) / 2;
	cout << res << '\n';
}

Compilation message

mergers.cpp: In function 'int32_t main()':
mergers.cpp:15:20: warning: statement has no effect [-Wunused-value]
   15 | #define debug(...) 0
      |                    ^
mergers.cpp:103:2: note: in expansion of macro 'debug'
  103 |  debug(AI(vir));
      |  ^~~~~
mergers.cpp:106:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |  for (int i = 0;i < vir.size();++i) {
      |                 ~~^~~~~~~~~~~~
mergers.cpp:108:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |   if (i+1 < vir.size())
      |       ~~~~^~~~~~~~~~~~
mergers.cpp:15:20: warning: statement has no effect [-Wunused-value]
   15 | #define debug(...) 0
      |                    ^
mergers.cpp:117:2: note: in expansion of macro 'debug'
  117 |  debug(AI(all));
      |  ^~~~~
mergers.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
mergers.cpp:128:4: note: in expansion of macro 'DE'
  128 |    DE(x, u);
      |    ^~
mergers.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
mergers.cpp:134:4: note: in expansion of macro 'DE'
  134 |    DE(x, u);
      |    ^~

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 24044 KB Output is correct
2 Correct 18 ms 24044 KB Output is correct
3 Correct 17 ms 24044 KB Output is correct
4 Correct 17 ms 24044 KB Output is correct
5 Correct 17 ms 24044 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 16 ms 23788 KB Output is correct
8 Correct 17 ms 24044 KB Output is correct
9 Correct 17 ms 24064 KB Output is correct
10 Correct 17 ms 24044 KB Output is correct
11 Correct 17 ms 24044 KB Output is correct
12 Correct 19 ms 24044 KB Output is correct
13 Correct 17 ms 24064 KB Output is correct
14 Incorrect 17 ms 24044 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 24044 KB Output is correct
2 Correct 18 ms 24044 KB Output is correct
3 Correct 17 ms 24044 KB Output is correct
4 Correct 17 ms 24044 KB Output is correct
5 Correct 17 ms 24044 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 16 ms 23788 KB Output is correct
8 Correct 17 ms 24044 KB Output is correct
9 Correct 17 ms 24064 KB Output is correct
10 Correct 17 ms 24044 KB Output is correct
11 Correct 17 ms 24044 KB Output is correct
12 Correct 19 ms 24044 KB Output is correct
13 Correct 17 ms 24064 KB Output is correct
14 Incorrect 17 ms 24044 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 24044 KB Output is correct
2 Correct 18 ms 24044 KB Output is correct
3 Correct 17 ms 24044 KB Output is correct
4 Correct 17 ms 24044 KB Output is correct
5 Correct 17 ms 24044 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 16 ms 23788 KB Output is correct
8 Correct 17 ms 24044 KB Output is correct
9 Correct 17 ms 24064 KB Output is correct
10 Correct 17 ms 24044 KB Output is correct
11 Correct 17 ms 24044 KB Output is correct
12 Correct 19 ms 24044 KB Output is correct
13 Correct 17 ms 24064 KB Output is correct
14 Incorrect 17 ms 24044 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 86 ms 38244 KB Output is correct
2 Correct 277 ms 41188 KB Output is correct
3 Incorrect 20 ms 24428 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 24044 KB Output is correct
2 Correct 18 ms 24044 KB Output is correct
3 Correct 17 ms 24044 KB Output is correct
4 Correct 17 ms 24044 KB Output is correct
5 Correct 17 ms 24044 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 16 ms 23788 KB Output is correct
8 Correct 17 ms 24044 KB Output is correct
9 Correct 17 ms 24064 KB Output is correct
10 Correct 17 ms 24044 KB Output is correct
11 Correct 17 ms 24044 KB Output is correct
12 Correct 19 ms 24044 KB Output is correct
13 Correct 17 ms 24064 KB Output is correct
14 Incorrect 17 ms 24044 KB Output isn't correct
15 Halted 0 ms 0 KB -