Submission #1267363

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267363		_filya_	Synchronization (JOI13_synchronization)	C++20	100 / 100	592 ms	77080 KiB

synchronization

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

using ll = long long;
using ld = long double;
using db = double;
using str = string;  // yay python!

using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;

using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;

#define tcT template <class T
#define tcTU tcT, class U
// ^ lol this makes everything look weird but I'll try it
tcT > using V = vector<T>;
tcT, size_t SZ > using AR = array<T, SZ>;
tcT > using PR = pair<T, T>;

// pairs
#define mp make_pair
#define f first
#define s second

// vectors
// oops size(x), rbegin(x), rend(x) need C++17
#define sz(x) int((x).size())
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define rall(x) x.rbegin(), x.rend()
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define eb emplace_back
#define pf push_front

#define lb lower_bound
#define ub upper_bound
tcT > int lwb(V<T> &a, const T &b) { return int(lb(all(a), b) - bg(a)); }

// loops
#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 trav(a, x) for (auto &a : x)

const int MOD = 1e9 + 7;  // 998244353;
const int MX = 2e5 + 5;
const ll INF = 1e18;  // not too close to LLONG_MAX
const ld PI = acos((ld)-1);
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};  // for every grid problem!!
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
template <class T> using pqg = priority_queue<T, vector<T>, greater<T>>;

// bitwise ops
// also see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
constexpr int pct(int x) { return __builtin_popcount(x); }  // # of bits set
constexpr int bits(int x) {  // assert(x >= 0); // make C++11 compatible until
	                         // USACO updates ...
	return x == 0 ? 0 : 31 - __builtin_clz(x);
}  // floor(log2(x))
constexpr int p2(int x) { return 1 << x; }
constexpr int msk2(int x) { return p2(x) - 1; }

ll cdiv(ll a, ll b) {
	return a / b + ((a ^ b) > 0 && a % b);
}  // divide a by b rounded up
ll fdiv(ll a, ll b) {
	return a / b - ((a ^ b) < 0 && a % b);
}  // divide a by b rounded down

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

tcTU > T fstTrue(T lo, T hi, U f) {
	hi++;
	assert(lo <= hi);  // assuming f is increasing
	while (lo < hi) {  // find first index such that f is true
		T mid = lo + (hi - lo) / 2;
		f(mid) ? hi = mid : lo = mid + 1;
	}
	return lo;
}
tcTU > T lstTrue(T lo, T hi, U f) {
	lo--;
	assert(lo <= hi);  // assuming f is decreasing
	while (lo < hi) {  // find first index such that f is true
		T mid = lo + (hi - lo + 1) / 2;
		f(mid) ? lo = mid : hi = mid - 1;
	}
	return lo;
}
tcT > void remDup(vector<T> &v) {  // sort and remove duplicates
	sort(all(v));
	v.erase(unique(all(v)), end(v));
}
tcTU > void erase(T &t, const U &u) {  // don't erase
	auto it = t.find(u);
	assert(it != end(t));
	t.erase(it);
}  // element that doesn't exist from (multi)set

// INPUT
#define tcTUU tcT, class... U
tcT > void re(complex<T> &c);
tcTU > void re(pair<T, U> &p);
tcT > void re(V<T> &v);
tcT, size_t SZ > void re(AR<T, SZ> &a);

tcT > void re(T &x) { cin >> x; }
void re(db &d) {
	str t;
	re(t);
	d = stod(t);
}
void re(ld &d) {
	str t;
	re(t);
	d = stold(t);
}
tcTUU > void re(T &t, U &...u) {
	re(t);
	re(u...);
}

tcT > void re(complex<T> &c) {
	T a, b;
	re(a, b);
	c = {a, b};
}
tcTU > void re(pair<T, U> &p) { re(p.f, p.s); }
tcT > void re(V<T> &x) { trav(a, x) re(a); }
tcT, size_t SZ > void re(AR<T, SZ> &x) { trav(a, x) re(a); }
tcT > void rv(int n, V<T> &x) {
	x.rsz(n);
	re(x);
}

// TO_STRING
#define ts to_string
str ts(char c) { return str(1, c); }
str ts(const char *s) { return (str)s; }
str ts(str s) { return s; }
str ts(bool b) {
#ifdef LOCAL
	return b ? "true" : "false";
#else
	return ts((int)b);
#endif
}
tcT > str ts(complex<T> c) {
	stringstream ss;
	ss << c;
	return ss.str();
}
str ts(V<bool> v) {
	str res = "{";
	F0R(i, sz(v)) res += char('0' + v[i]);
	res += "}";
	return res;
}
template <size_t SZ> str ts(bitset<SZ> b) {
	str res = "";
	F0R(i, SZ) res += char('0' + b[i]);
	return res;
}
tcTU > str ts(pair<T, U> p);
tcT > str ts(T v) {  // containers with begin(), end()
#ifdef LOCAL
	bool fst = 1;
	str res = "{";
	for (const auto &x : v) {
		if (!fst) res += ", ";
		fst = 0;
		res += ts(x);
	}
	res += "}";
	return res;
#else
	bool fst = 1;
	str res = "";
	for (const auto &x : v) {
		if (!fst) res += " ";
		fst = 0;
		res += ts(x);
	}
	return res;

#endif
}
tcTU > str ts(pair<T, U> p) {
#ifdef LOCAL
	return "(" + ts(p.f) + ", " + ts(p.s) + ")";
#else
	return ts(p.f) + " " + ts(p.s);
#endif
}

// OUTPUT
tcT > void pr(T x) { cout << ts(x); }
tcTUU > void pr(const T &t, const U &...u) {
	pr(t);
	pr(u...);
}
void ps() { pr("\n"); }  // print w/ spaces
tcTUU > void ps(const T &t, const U &...u) {
	pr(t);
	if (sizeof...(u)) pr(" ");
	ps(u...);
}

// DEBUG
void DBG() { cerr << "]" << endl; }
tcTUU > void DBG(const T &t, const U &...u) {
	cerr << ts(t);
	if (sizeof...(u)) cerr << ", ";
	DBG(u...);
}
#ifdef LOCAL  // compile with -DLOCAL, chk -> fake assert
#define dbg(...)                                                                       \
	cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#define chk(...)                                                                       \
	if (!(__VA_ARGS__))                                                                \
		cerr << "Line(" << __LINE__ << ") -> function(" << __FUNCTION__                \
		     << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n",                   \
		    exit(0);
#else
#define dbg(...) 0
#define chk(...) 0
#endif

void setPrec() { cout << fixed << setprecision(15); }
void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
// FILE I/O
void setIn(str s) { freopen(s.c_str(), "r", stdin); }
void setOut(str s) { freopen(s.c_str(), "w", stdout); }
void setIO(str s = "") {
	unsyncIO();
	setPrec();
	// cin.exceptions(cin.failbit);
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(s)) setIn(s + ".in"), setOut(s + ".out");  // for USACO
}

vpi adj[MX];
int N, M, Q, ans[MX];
vi change[MX];
vpi bad[MX];

bool done[MX];         // processed as centroid yet
int sub[MX], cen[MX];  // subtree size, centroid anc
map<int, list<int>> to[MX], from[MX];
void dfs(int x, int p) {
	sub[x] = 1;
	trav(y, adj[x]) if (!done[y.f] && y.f != p) dfs(y.f, x), sub[x] += sub[y.f];
}
int centroid(int x) {
	dfs(x, -1);
	for (int sz = sub[x];;) {
		pi mx = {0, 0};
		trav(y, adj[x]) if (!done[y.f] && sub[y.f] < sub[x]) ckmax(mx, {sub[y.f], y.f});
		if (mx.f * 2 <= sz) return x;
		x = mx.s;
	}
}
void ad(list<int> &a, list<int> &b) {
	a.splice(end(a), b);
	assert(!sz(b));
}
void merge(map<int, list<int>> &a, map<int, list<int>> &b) {
	if (sz(a) < sz(b)) swap(a, b);
	trav(t, b) ad(a[t.f], t.s);
	b.clear();
}

void getAll(list<int> &x, map<int, list<int>> &a, pi p) {
	while (1) {
		auto it = a.ub(p.f);
		if (it == end(a) || it->f >= p.s) break;
		ad(x, it->s);
		a.erase(it);
	}
}

void oops(int a, int b) {
	trav(t, adj[a]) if (!done[t.f] && t.f != b) {
		oops(t.f, a);
		trav(z, bad[t.s]) {
			{
				list<int> x;
				getAll(x, to[t.f], z);
				if (sz(x)) ad(to[t.f][z.f], x);
			}
			{
				list<int> x;
				getAll(x, from[t.f], z);
				if (sz(x)) ad(from[t.f][z.s], x);
			}
		}
		merge(to[a], to[t.f]), merge(from[a], from[t.f]);
	}
	to[a][M + 1].pb(a);
	from[a][0].pb(a);
}

int comp[MX];

void makeLabel(int a, int b, int cnt) {
	comp[a] = cnt;
	trav(t, adj[a]) if (!done[t.f] && t.f != b) makeLabel(t.f, a, cnt);
}

int genLabel(int x) {
	comp[x] = 0;
	int cnt = 1;
	trav(y, adj[x]) if (!done[y.f]) { makeLabel(y.f, x, cnt++); }
	return cnt;
}

void gen(int CEN, int _x) {  // CEN = centroid above x
	int x = centroid(_x);
	done[x] = 1;
	cen[x] = CEN;
	sub[x] = sub[_x];
	int num = genLabel(x);
	oops(x, -1);
	vi cnt(num);
	vector<pair<int, list<int>>> TO(all(to[x]));
	vector<pair<int, list<int>>> FROM(all(from[x]));
	int ind = 0, sum = 0;
	trav(t, TO) {
		while (ind < sz(FROM) && FROM[ind].f <= t.f) {
			trav(u, FROM[ind].s) cnt[comp[u]]++, sum++;
			ind++;
		}
		trav(u, t.s) {
			ans[u] += sum;
			if (comp[u]) ans[u] -= cnt[comp[u]];
		}
	}
	to[x].clear(), from[x].clear();
	trav(y, adj[x]) if (!done[y.f]) gen(x, y.f);
}

void init(int _N) {
	N = _N;
	FOR(i, 1, N + 1) done[i] = 0;
	gen(-1, 1);
}  // start at vert 1

int main() {
	setIO();
	re(N, M, Q);
	F0R(i, N - 1) {
		int X, Y;
		re(X, Y);
		adj[X].pb({Y, i}), adj[Y].pb({X, i});
	}
	F0R(i, N - 1) change[i].pb(-5);
	FOR(i, 1, M + 1) {
		int D;
		re(D);
		D--;
		change[D].pb(i);
	}
	F0R(i, N - 1) {
		if (sz(change[i]) & 1) change[i].pb(M + 5);
		for (int j = 0; j < sz(change[i]); j += 2)
			bad[i].pb({change[i][j], change[i][j + 1]});
	}
	init(N);
	F0R(i, Q) {
		int c;
		re(c);
		ps(ans[c]);
	}
}

Compilation message (stderr)

synchronization.cpp: In function 'void setIn(str)':
synchronization.cpp:248:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  248 | void setIn(str s) { freopen(s.c_str(), "r", stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp: In function 'void setOut(str)':
synchronization.cpp:249:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  249 | void setOut(str s) { freopen(s.c_str(), "w", stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40