Submission #431069

#	Time	Username	Problem	Language	Result	Execution time	Memory
431069		Kevin_Zhang_TW	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	17 / 100	5011 ms	40664 KiB

joitter2

#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
// My bug list :
// integer overflow
// 0based, 1based forgotten
// index out of bound
// n, m, i, j typo
// some cases are missing
 
const int MAX_N = 100010;
 
ll ans;
 
int n, m, g[MAX_N], sz[MAX_N];
 
//unordered_set<int> in[MAX_N], out[MAX_N];
set< pair<int,int> > in[MAX_N];//, out[MAX_N];
 
set<int> out[MAX_N];
 
void init() {
	iota(g, g+n+1, 0);
	fill(sz, sz + n + 1, 1);
}
 
int F(int i) { return i == g[i] ? i : g[i] = F(g[i]); }
 
pair<int,int> tok(int i) {
	return make_pair(F(i), i);
}
 
 
void kill_edge(int a, int b) {
	in[F(b)].erase(tok(a));
	out[F(a)].erase(F(b));
}
 
void clean(int a, int b) {
	vector<int> ina;//(AI(in[a]));
	for (auto [g, id] : in[a]) ina.pb(id);
	for (int x : ina) {
		if (F(x) == b) {
			kill_edge(x, a);
			ans -= sz[ a ];
		}
	}
}
 
void resetg(set<pair<int,int>> &st, int a, int b) {
	auto it = st.lower_bound(make_pair(a, -1));
	vector<pair<int,int>> pt;
	while (it != end(st) && it->first == a) {
		pt.pb(*it);
		it = st.erase(it);
	}
	for (auto [x, y] : pt)
		st.insert({b, y});
}
 
void kick(int a, int b) {
	auto it = in[a].lower_bound(make_pair(b, -1));
	vector<pair<int,int>> pt;
	while (it != end(in[a]) && it->first == b)
		pt.pb(*it++);
	for (auto [_, y] : pt) {
		kill_edge(y, a);
		ans -= sz[a];
	}
}
 
void add_edge(int a, int b) {
	if (F(a) == F(b)) return;
	if (in[ F(b) ].count(tok(a))) return;
	ans += sz[ F(b) ];
	in[F(b)].insert(tok(a));
	out[F(a)].insert(F(b));
 
	if (out[F(b)].count(F(a))) {
		a = F(a), b = F(b);
 
		kick(a, b), kick(b, a);
 
		vector<pair<int,int>> kl;
		for (auto [g, id] : in[a]) {
			kl.pb(id, a);
			DE(a, b, F(id));
			assert(F(id) != F(b));
		}
		for (auto [g, id] : in[b]) {
		   	kl.pb(id, b);
			assert(F(id) != F(a));
		}
 
		for (auto [a, b] : kl) {
			kill_edge(a, b);
			ans -= sz[b];
		}
 
		for (int g : out[a])
			resetg(in[g], a, b);
 
		//ans -= 1ll * sz[a] * in[a].size() + 1ll * sz[b] * in[b].size();
		ans += 2ll * sz[a] * sz[b];
 
		g[a] = b;
		sz[b] += sz[a];
 
		out[b].insert(AI(out[a]));
		out[a].clear();
 
		for (auto [a, b] : kl) add_edge(a, b);
	}
}
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> m;
	init();
	while (m--) {
		int a, b;
		cin >> a >> b;
		add_edge(a, b);
		cout << ans << '\n';
   	}
}

Compilation message (stderr)

joitter2.cpp: In function 'void add_edge(int, int)':
joitter2.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
joitter2.cpp:100:4: note: in expansion of macro 'DE'
  100 |    DE(a, b, F(id));
      |    ^~

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 0 / 83