oj.uz

Submission #350305

# Submission time Handle Problem Language Result Execution time Memory
350305 2021-01-19T04:52:19 Z Kevin_Zhang_TW Parachute rings (IOI12_rings) C++17
20 / 100
 2813 ms 60524 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 pushbig(int id) {
	if (id == over) 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;
	}

// 	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
	int verybig = 0;
	for (int x : big) {
		if (edge[x].size() > 3) ++verybig;
		canpush(x);
		for (int u : edge[x]) canpush(u);
	}
	if (verybig > 1) {
		return glob = -1, void();
	}
	// 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;
	}
	if (glob == 0) glob = -1;


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

int CountCritical() {
	if (glob == -1) return 0;
	return glob;
}

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:96:2: note: in expansion of macro 'DE'
   96 |  DE(a, b);
      |  ^~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 23936 KB Output is correct
2 Correct 625 ms 24172 KB Output is correct
3 Correct 1869 ms 24300 KB Output is correct
4 Correct 19 ms 23916 KB Output is correct
5 Correct 22 ms 24044 KB Output is correct
6 Correct 19 ms 24200 KB Output is correct
7 Correct 20 ms 23916 KB Output is correct
8 Correct 19 ms 24044 KB Output is correct
9 Correct 1018 ms 24172 KB Output is correct
10 Correct 837 ms 24172 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Runtime error 64 ms 60524 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 18 ms 23936 KB Output is correct
2 Correct 625 ms 24172 KB Output is correct
3 Correct 1869 ms 24300 KB Output is correct
4 Correct 19 ms 23916 KB Output is correct
5 Correct 22 ms 24044 KB Output is correct
6 Correct 19 ms 24200 KB Output is correct
7 Correct 20 ms 23916 KB Output is correct
8 Correct 19 ms 24044 KB Output is correct
9 Correct 1018 ms 24172 KB Output is correct
10 Correct 837 ms 24172 KB Output is correct
11 Correct 900 ms 24172 KB Output is correct
12 Correct 367 ms 24556 KB Output is correct
13 Incorrect 2813 ms 24636 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 23936 KB Output is correct
2 Correct 625 ms 24172 KB Output is correct
3 Correct 1869 ms 24300 KB Output is correct
4 Correct 19 ms 23916 KB Output is correct
5 Correct 22 ms 24044 KB Output is correct
6 Correct 19 ms 24200 KB Output is correct
7 Correct 20 ms 23916 KB Output is correct
8 Correct 19 ms 24044 KB Output is correct
9 Correct 1018 ms 24172 KB Output is correct
10 Correct 837 ms 24172 KB Output is correct
11 Correct 900 ms 24172 KB Output is correct
12 Correct 367 ms 24556 KB Output is correct
13 Incorrect 2813 ms 24636 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 23936 KB Output is correct
2 Correct 625 ms 24172 KB Output is correct
3 Correct 1869 ms 24300 KB Output is correct
4 Correct 19 ms 23916 KB Output is correct
5 Correct 22 ms 24044 KB Output is correct
6 Correct 19 ms 24200 KB Output is correct
7 Correct 20 ms 23916 KB Output is correct
8 Correct 19 ms 24044 KB Output is correct
9 Correct 1018 ms 24172 KB Output is correct
10 Correct 837 ms 24172 KB Output is correct
11 Runtime error 64 ms 60524 KB Execution killed with signal 6 (could be triggered by violating memory limits)
12 Halted 0 ms 0 KB -