제출 #939492

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
939492		WonderfulWhale	조이터에서 친구를 만드는건 재밌어 (JOI20_joitter2)	C++17	100 / 100	1946 ms	119212 KiB

joitter2

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

#define int int64_t
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

const int MAXN = 100'009;

int cnt[MAXN];
int p[MAXN];
int sz[MAXN];
int sum[MAXN];
vector<int> V[MAXN];
map<int, int> in[MAXN];
map<int, int> out[MAXN];
set<int> In[MAXN];
set<int> Out[MAXN];
//set<int> in[MAXN];
//set<int> out[MAXN];
int ans;

int Find(int x) {
	return x==p[x]?x:p[x]=Find(p[x]);
}

void Union(int a, int b) {
	a = Find(a);
	b = Find(b);
	if(a==b) return;
	//cout << "before: " << sz[a] << " " << sum[a] << "\n";
	//cout << "before: " << sz[b] << " " << sum[b] << "\n";
	ans -= sz[a]*sz(In[a]);
	ans -= sz[b]*sz(In[b]);
	ans -= sz[a]*(sz[a]-1);
	ans -= sz[b]*(sz[b]-1);
	//cerr << "started ans: " << ans << "\n";
	vector<int> union_queue;
	if(sz(out[a])+sz(in[a])<sz(out[b])+sz(in[b])) swap(a, b);
	//cerr << "SDOJFDSF: "<< a << " " << b << "\n";
	for(int x:In[a]) {
		//cerr << "? " << x << "\n";
	}
	for(int x:In[b]) {
		//cerr << "! " << x << "\n";
	}
	for(pii x:out[b]) {
		if(x.st==a) continue;
		if(in[a].count(x.st)) {
			union_queue.pb(x.st);
		}
		out[a][x.st]+=x.nd;
		//out[a].insert(x);
		in[x.st][a] += in[x.st][b];
		in[x.st].erase(b);
		//in[x].erase(b);
		//in[x].insert(a);
	}
	for(int x:In[b]) {
		if(Find(x)!=a) {
			In[a].insert(x);
		}
	}
	for(int x:V[b]) {
		//cerr << " we will be thereby erasing: " << x << "\n";
		In[a].erase(x);
		V[a].pb(x);
	}
	V[b].clear();

	out[b].clear();
	for(pii x:in[b]) {
		if(x.st==a) continue;
		if(out[a].count(x.st)) {
			union_queue.pb(x.st);
		}
		in[a][x.st]+=x.nd;
		//cerr << "some susus\n";
		//cerr << x.st << " " << x.nd << "\n";
		sum[a]+=x.nd;
		//in[a].insert(x);
		out[x.st][a] += out[x.st][b];
		out[x.st].erase(b);
		//out[x].erase(b);
		//out[x].insert(a);
	}
	in[b].clear();
	p[b] = a;
	sz[a] += sz[b];
	//cerr <<" here : " << ans << "\n";
	ans += sz[a]*(sz[a]-1);
	ans += sz[a]*sz(In[a]);
	for(int x:In[a]) {
		//cout << "-> " << x << "\n";
	}
	//cerr << "here: " << ans << "\n";
	//cerr << "after: " << sz[a] << " " << sz(In[a]) << "\n";
	//cerr << "after mergin\n";
	for(int x:union_queue) {
		Union(a, x);
	}
}

set<pii> S;
set<int> used[MAXN];

int32_t main() {
    //ios_base::sync_with_stdio(false);
    //cin.tie(NULL);

	int n, m;
	cin >> n >> m;
	iota(p, p+n+1, 0);
	fill(sz, sz+n+1, 1);
	for(int i=1;i<=n;i++) {
		V[i].pb(i);
	}
	for(int i=0;i<m;i++) {
		int a, b;
		cin >> a >> b;
		S.insert({a, b});
		int A = Find(a);
		int B = Find(b);
		if(A==B) goto skip;
		//out[A].insert(B);
		out[A][B]++;
		//in[B].insert(A);
		if(in[A].count(B)) {
			Union(A, B);
		} else {
			//cerr << "HERE\n";
			ans -= sz[B]*sz(In[B]);
			in[B][A]++;
			sum[B]++;
			In[B].insert(a);
			Out[a].insert(B);
			//cerr << "new sum: "<< B << " " << sum[B] << "\n";
			ans += sz[B]*sz(In[B]);
		}
		skip:
		//int cnt = 0;
		//for(int i=1;i<=n;i++) {
			//used[i].clear();
		//}
		//for(pii x:S) {
			//if(Find(x.st)==Find(x.nd)) continue;
			//if(used[x.st].count(Find(x.nd))) continue;
			//cnt += sz[Find(x.nd)];
			//used[x.st].insert(Find(x.nd));
		//}
		//cerr << ans << " " << cnt << "\n";
		cout << ans << "\n";
	}
}

컴파일 시 표준 에러 (stderr) 메시지

joitter2.cpp: In function 'void Union(int64_t, int64_t)':
joitter2.cpp:45:10: warning: unused variable 'x' [-Wunused-variable]
   45 |  for(int x:In[a]) {
      |          ^
joitter2.cpp:48:10: warning: unused variable 'x' [-Wunused-variable]
   48 |  for(int x:In[b]) {
      |          ^
joitter2.cpp:97:10: warning: unused variable 'x' [-Wunused-variable]
   97 |  for(int x:In[a]) {
      |          ^

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