oj.uz

Submission #350342

# Submission time Handle Problem Language Result Execution time Memory
350342 2021-01-19T05:09:33 Z Kevin_Zhang_TW Parachute rings (IOI12_rings) C++17
20 / 100
 2794 ms 60780 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);
	assert(N <= 20000);
// 	for (int i = 0;i < N;++i)
// 		adsu[i] = dsu(N, N-1);
}

vector<pair<int,int>> alledge;
// TODO big crisis
// new edge is {a, b}
int over = -1;

void superbig(int id) {
	if (over == -1) {
		over = id;
		forone = dsu(N, N-1);
		for (auto [a, b] : alledge)
			if (a != id && b != id)
				forone.M(a, b);
		glob = forone.noring();
	}
	else if (over != id) {
		glob = -1;
		return;
	}
	else {
		auto [a, b] = alledge.back();
		if (a != id && b != id)
			forone.M(a, b);
		glob = forone.noring();
	}
}
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;
	}

// 	pushbig(a), pushbig(b);
// 
// 	if (over != -1) {
// 		if (a != over && b != over)
// 			forone.M(a, b);
// 		glob = forone.getans() == N - 1 ? 1 : -1;
// 	}

// 
// 	// 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();


	for (int x : can) {
		dsu D(N, N - 1);

		for (auto [a, b] : alledge) if (a != x && b != x) 
			D.M(a, b);

		if (D.noring()) ++glob;
	}

}
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);

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

	alledge.pb(A, B);

// 	if (over != -1) {
// 	   superbig(over);
// 	   return;
// 	}

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

int CountCritical() {
	if (over != -1) {
		dsu now(N, N-1);
		for (auto [a, b] : alledge)
			if (a != over && b != over)
				now.M(a, b);
		return now.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 adjust(int, int)':
rings.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
rings.cpp:112:2: note: in expansion of macro 'DE'
  112 |  DE(a, b);
      |  ^~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 637 ms 24428 KB Output is correct
3 Correct 1814 ms 24256 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 20 ms 24172 KB Output is correct
7 Correct 42 ms 23916 KB Output is correct
8 Correct 22 ms 24044 KB Output is correct
9 Correct 999 ms 24300 KB Output is correct
10 Correct 822 ms 24320 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Runtime error 63 ms 60780 KB Execution killed with signal 6 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 637 ms 24428 KB Output is correct
3 Correct 1814 ms 24256 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 20 ms 24172 KB Output is correct
7 Correct 42 ms 23916 KB Output is correct
8 Correct 22 ms 24044 KB Output is correct
9 Correct 999 ms 24300 KB Output is correct
10 Correct 822 ms 24320 KB Output is correct
11 Correct 908 ms 24300 KB Output is correct
12 Correct 361 ms 24556 KB Output is correct
13 Incorrect 2794 ms 24684 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 637 ms 24428 KB Output is correct
3 Correct 1814 ms 24256 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 20 ms 24172 KB Output is correct
7 Correct 42 ms 23916 KB Output is correct
8 Correct 22 ms 24044 KB Output is correct
9 Correct 999 ms 24300 KB Output is correct
10 Correct 822 ms 24320 KB Output is correct
11 Correct 908 ms 24300 KB Output is correct
12 Correct 361 ms 24556 KB Output is correct
13 Incorrect 2794 ms 24684 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23788 KB Output is correct
2 Correct 637 ms 24428 KB Output is correct
3 Correct 1814 ms 24256 KB Output is correct
4 Correct 17 ms 23916 KB Output is correct
5 Correct 18 ms 24044 KB Output is correct
6 Correct 20 ms 24172 KB Output is correct
7 Correct 42 ms 23916 KB Output is correct
8 Correct 22 ms 24044 KB Output is correct
9 Correct 999 ms 24300 KB Output is correct
10 Correct 822 ms 24320 KB Output is correct
11 Runtime error 63 ms 60780 KB Execution killed with signal 6 (could be triggered by violating memory limits)
12 Halted 0 ms 0 KB -