oj.uz

Submission #350362

# Submission time Handle Problem Language Result Execution time Memory
350362 2021-01-19T05:16:33 Z Kevin_Zhang_TW Parachute rings (IOI12_rings) C++17
100 / 100
 2507 ms 232432 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 = 1000005;

int N, glob;

struct dsu {
	vector<int> g, sz, deg;

	int n, badcnt, allbad, answer;

	dsu() {};
	dsu (int n, int size) : n(n), answer(size), badcnt(0), allbad(0) { 
		deg = g = vector<int>(n);
		sz = vector<int>(n, 1);
		iota(AI(g), 0); 
	}

	int F(int i) { return i == g[i] ? i : g[i] = F(g[i]); }

	void M(int a, int b) { 

		if (max(++deg[a], ++deg[b]) >= 3) allbad = true;

		if (allbad) return;

		a = F(a), b = F(b);
		if (sz[a] < sz[b]) swap(a, b);

		if (a != b) {
			return sz[a] += sz[b], g[b] = a, void();
		}
		if (++badcnt == 2) allbad = true;
		// merging into a ring
		// which means you have to remove objects on the ring
		// all of them is ok, since max deg is 2
		// I only care when max deg is <= 2
		// and a ring cannot merge with other for max deg <= 2
		answer = sz[a];
	}
	bool noring() { return badcnt == 0 && allbad == false; }

	int getans() { 
		return allbad ? 0 : answer;
	}
};

dsu alld, forone;

vector<int> edge[MAX_N];

bool iscan[MAX_N];

vector<int> big, can;

vector<dsu> forcan;

void canpush(int id) { if (iscan[id]) return; iscan[id] = true, can.pb(id); }

void Init(int N_) {
	N = N_;
	glob = N;
	alld = dsu(N, N);
}

vector<pair<int,int>> alledge;
int over = -1;
void makebig() {
	static int lst = 0;
	if (lst == 0)
		forone = dsu(N, N-1);
	while (lst < alledge.size()) {
		auto [a, b] = alledge[lst++];
		if (a != over && b != over)
			forone.M(a, b);
	}
}
void superbig(int id) {
	if (over == -1) {
		over = id;
		return;
	}
	else if (over != id) {
		glob = -1;
		return;
	}
}
void adjust(int a, int b) {
	if (glob == -1) return;

	DE(a, b);

	if (big.empty()) {
		assert(can.empty());

		alld.M(a, b);

		glob = alld.getans();

		return;
	}

 	// deal with old ones
 	int oldsize = can.size();
 	for (int i = 0;i < oldsize;++i) {
 		int x = can[i];
 		if (a != x && b != x)
 			forcan[i].M(a, b);
 	}
 
	// put new element into candidate
	for (int x : big) {
		// assert(edge[x].size() <= 3);
		canpush(x);
		for (int u : edge[x]) canpush(u);
	}
	// examine new candidates
 
 	for (int i = oldsize;i < can.size();++i) {
 		forcan.pb(N, N-1);
 		int x = can[i];
 		for (auto [a, b] : alledge) if (a != x && b != x) {
 			forcan[i].M(a, b);
 		}
 	}

	// assert(forcan.size() == can.size());

	glob = 0;

 	// examine all candidates
 	for (int i = 0;i < can.size();++i) 
 		glob += forcan[i].noring();

}
void Link(int A, int B) {
	if (glob == -1) return;

	edge[A].pb(B), edge[B].pb(A);

	if (edge[A].size() == 3) big.pb(A);
	if (edge[B].size() == 3) big.pb(B);

	alledge.pb(A, B);

 	if (edge[A].size() > 3) superbig(A);
 	if (edge[B].size() > 3) superbig(B);

	if (over != -1) return makebig(), void();

 	if (big.size() > 4) {
 		glob = -1;
 		return;
 	}
	
	adjust(A, B);
}

int CountCritical() {
	if (glob == -1) return 0;
	if (over != -1) return forone.noring();
	return max(glob, 0);
}

Compilation message

rings.cpp: In constructor 'dsu::dsu(int, int)':
rings.cpp:25:25: warning: 'dsu::answer' will be initialized after [-Wreorder]
   25 |  int n, badcnt, allbad, answer;
      |                         ^~~~~~
rings.cpp:25:9: warning:   'int dsu::badcnt' [-Wreorder]
   25 |  int n, badcnt, allbad, answer;
      |         ^~~~~~
rings.cpp:28:2: warning:   when initialized here [-Wreorder]
   28 |  dsu (int n, int size) : n(n), answer(size), badcnt(0), allbad(0) {
      |  ^~~
rings.cpp: In function 'void makebig()':
rings.cpp:87:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   87 |  while (lst < alledge.size()) {
      |         ~~~~^~~~~~~~~~~~~~~~
rings.cpp: In function 'void adjust(int, int)':
rings.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
rings.cpp:106:2: note: in expansion of macro 'DE'
  106 |  DE(a, b);
      |  ^~
rings.cpp:134:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  134 |   for (int i = oldsize;i < can.size();++i) {
      |                        ~~^~~~~~~~~~~~
rings.cpp:147:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  147 |   for (int i = 0;i < can.size();++i)
      |                  ~~^~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 19 ms 24300 KB Output is correct
3 Correct 19 ms 24428 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 19 ms 24172 KB Output is correct
7 Correct 20 ms 24812 KB Output is correct
8 Correct 18 ms 24044 KB Output is correct
9 Correct 21 ms 24428 KB Output is correct
10 Correct 22 ms 24556 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 565 ms 50284 KB Output is correct
2 Correct 1319 ms 111580 KB Output is correct
3 Correct 411 ms 189948 KB Output is correct
4 Correct 1293 ms 74700 KB Output is correct
5 Correct 1295 ms 74668 KB Output is correct
6 Correct 1258 ms 73424 KB Output is correct
7 Correct 453 ms 224616 KB Output is correct
8 Correct 2066 ms 137224 KB Output is correct
9 Correct 2507 ms 156776 KB Output is correct
10 Correct 867 ms 72544 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 19 ms 24300 KB Output is correct
3 Correct 19 ms 24428 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 19 ms 24172 KB Output is correct
7 Correct 20 ms 24812 KB Output is correct
8 Correct 18 ms 24044 KB Output is correct
9 Correct 21 ms 24428 KB Output is correct
10 Correct 22 ms 24556 KB Output is correct
11 Correct 20 ms 24428 KB Output is correct
12 Correct 24 ms 25836 KB Output is correct
13 Correct 25 ms 25452 KB Output is correct
14 Correct 20 ms 24812 KB Output is correct
15 Correct 20 ms 25452 KB Output is correct
16 Correct 21 ms 24428 KB Output is correct
17 Correct 21 ms 25836 KB Output is correct
18 Correct 23 ms 27884 KB Output is correct
19 Correct 22 ms 24428 KB Output is correct
20 Correct 24 ms 25196 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 19 ms 24300 KB Output is correct
3 Correct 19 ms 24428 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 19 ms 24172 KB Output is correct
7 Correct 20 ms 24812 KB Output is correct
8 Correct 18 ms 24044 KB Output is correct
9 Correct 21 ms 24428 KB Output is correct
10 Correct 22 ms 24556 KB Output is correct
11 Correct 20 ms 24428 KB Output is correct
12 Correct 24 ms 25836 KB Output is correct
13 Correct 25 ms 25452 KB Output is correct
14 Correct 20 ms 24812 KB Output is correct
15 Correct 20 ms 25452 KB Output is correct
16 Correct 21 ms 24428 KB Output is correct
17 Correct 21 ms 25836 KB Output is correct
18 Correct 23 ms 27884 KB Output is correct
19 Correct 22 ms 24428 KB Output is correct
20 Correct 24 ms 25196 KB Output is correct
21 Correct 38 ms 25704 KB Output is correct
22 Correct 52 ms 26852 KB Output is correct
23 Correct 62 ms 27628 KB Output is correct
24 Correct 68 ms 32460 KB Output is correct
25 Correct 35 ms 31212 KB Output is correct
26 Correct 69 ms 33252 KB Output is correct
27 Correct 72 ms 28212 KB Output is correct
28 Correct 60 ms 41836 KB Output is correct
29 Correct 57 ms 44396 KB Output is correct
30 Correct 99 ms 28940 KB Output is correct

Subtask #5
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 19 ms 24300 KB Output is correct
3 Correct 19 ms 24428 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 19 ms 24172 KB Output is correct
7 Correct 20 ms 24812 KB Output is correct
8 Correct 18 ms 24044 KB Output is correct
9 Correct 21 ms 24428 KB Output is correct
10 Correct 22 ms 24556 KB Output is correct
11 Correct 565 ms 50284 KB Output is correct
12 Correct 1319 ms 111580 KB Output is correct
13 Correct 411 ms 189948 KB Output is correct
14 Correct 1293 ms 74700 KB Output is correct
15 Correct 1295 ms 74668 KB Output is correct
16 Correct 1258 ms 73424 KB Output is correct
17 Correct 453 ms 224616 KB Output is correct
18 Correct 2066 ms 137224 KB Output is correct
19 Correct 2507 ms 156776 KB Output is correct
20 Correct 867 ms 72544 KB Output is correct
21 Correct 20 ms 24428 KB Output is correct
22 Correct 24 ms 25836 KB Output is correct
23 Correct 25 ms 25452 KB Output is correct
24 Correct 20 ms 24812 KB Output is correct
25 Correct 20 ms 25452 KB Output is correct
26 Correct 21 ms 24428 KB Output is correct
27 Correct 21 ms 25836 KB Output is correct
28 Correct 23 ms 27884 KB Output is correct
29 Correct 22 ms 24428 KB Output is correct
30 Correct 24 ms 25196 KB Output is correct
31 Correct 38 ms 25704 KB Output is correct
32 Correct 52 ms 26852 KB Output is correct
33 Correct 62 ms 27628 KB Output is correct
34 Correct 68 ms 32460 KB Output is correct
35 Correct 35 ms 31212 KB Output is correct
36 Correct 69 ms 33252 KB Output is correct
37 Correct 72 ms 28212 KB Output is correct
38 Correct 60 ms 41836 KB Output is correct
39 Correct 57 ms 44396 KB Output is correct
40 Correct 99 ms 28940 KB Output is correct
41 Correct 261 ms 43464 KB Output is correct
42 Correct 900 ms 99420 KB Output is correct
43 Correct 320 ms 96612 KB Output is correct
44 Correct 529 ms 232000 KB Output is correct
45 Correct 637 ms 155744 KB Output is correct
46 Correct 854 ms 78148 KB Output is correct
47 Correct 1129 ms 79088 KB Output is correct
48 Correct 435 ms 232432 KB Output is correct
49 Correct 822 ms 77148 KB Output is correct
50 Correct 912 ms 76516 KB Output is correct
51 Correct 343 ms 89476 KB Output is correct
52 Correct 395 ms 181512 KB Output is correct
53 Correct 387 ms 231788 KB Output is correct
54 Correct 1813 ms 142460 KB Output is correct
55 Correct 1179 ms 132884 KB Output is correct