oj.uz

답안 #227060

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
227060 2020-04-26T00:08:47 Z abeker Matching (COCI20_matching) C++17
58 / 110
 799 ms 524292 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef pair <int, int> pii;
 
const int MAXN = 1e5 + 5;
const int offset = 1 << 17;
const int MAXV = 1e8 + 5;

struct Node {
	int val;
	Node* nxt;
};

class Graph {
	Node* get_node(int dest, Node* head) {
		Node* newNode = new Node;
		newNode -> val = dest;
		newNode -> nxt = head;
		return newNode;
	}
	int N;
	public:
		Node **head;
		Graph(int N) {
			head = new Node*[N]();
			this -> N = N;
			for (int i = 0; i < N; i++)
				head[i] = nullptr;
		}
		Graph(){}
		void add(int src, int dest) {
			head[src] = get_node(dest, head[src]);
		}
		~Graph() {
			for (int i = 0; i < N; i++)
				delete[] head[i];
			delete[] head;
		}
};

int n;
stack <int> order;
pii edges[MAXV];
int e;

inline int add_variables(int vars) {
	n += vars;
	return n - vars;
}

void add_edge(int u, int v) {
	edges[e++] = {u, v};
}

void add_implication(int u1, int neg1, int u2, int neg2) {
	add_edge(2 * u1 + neg1, 2 * u2 + neg2);
	add_edge(2 * u2 + !neg2, 2 * u1 + !neg1);
}

void dfs_forward(int x, Graph &g, char *vis) {
	vis[x] = 1;
	for (Node* ptr = g.head[x]; ptr != nullptr; ptr = ptr -> nxt)
		if (!vis[ptr -> val])
			dfs_forward(ptr -> val, g, vis);
	order.push(x);
}

void bye() {
	puts("NE");
	exit(0);
}

void dfs_backward(int x, Graph &g, char *vis, bool *ans) {
	if (vis[x ^ 1] == -1)
		bye();
	vis[x] = -1;
	ans[x] = vis[x ^ 1];
	for (Node* ptr = g.head[x]; ptr != nullptr; ptr = ptr -> nxt)
		if (!vis[ptr -> val])
			dfs_backward(ptr -> val, g, vis, ans);
	vis[x] = 1;
}

int N;
int x[MAXN], y[MAXN];
vector <pii> tour[2 * offset];
int st[2 * offset], off[2 * offset];
vector <int> hor[MAXN], ver[MAXN];
unordered_map <int, pii> segs;
vector <int> graph[MAXN];
 
void load() {
	scanf("%d", &N);
	for (int i = 0; i < N; i++) {
		scanf("%d%d", x + i, y + i);
		hor[y[i]].push_back(i);
		ver[x[i]].push_back(i);
	}
}
 
void insert(int x, int lo, int hi, int from, int to, int var, int height) {
	if (lo >= to || hi <= from)	
		return;
	if (lo >= from && hi <= to) {
		tour[x].push_back({height, var});
		return;
	}
	int mid = (lo + hi) / 2;
	insert(2 * x, lo, mid, from, to, var, height);
	insert(2 * x + 1, mid, hi, from, to, var, height);
}
 
inline int get_id(int node, int x) {
	return x < off[node] ? st[node] + x : tour[node][x - off[node]].second;
}
 
void add_clause(int x, int u, int v) {
	if (u < off[x] + tour[x].size())
		add_implication(get_id(x, u), 0, get_id(x, v), 0);
}
	
void init(int x) {
	if (tour[x].empty())
		return;
	off[x] = 1;
	sort(tour[x].begin(), tour[x].end());
	while (off[x] < tour[x].size())
		off[x] *= 2;
	st[x] = add_variables(2 * off[x]);
	for (int i = 0; i < off[x]; i++) {
		add_clause(x, 2 * i, i);
		add_clause(x, 2 * i + 1, i);
	}
}
 
int get_bounds(int x, int val) {
	int lo = 0, hi = tour[x].size();
	while (lo < hi) {
		int mid = (lo + hi) / 2;
		if (tour[x][mid].first >= val)
			hi = mid;
		else
			lo = mid + 1;
	}
	return lo;
}
 
void update(int node, int from, int to, int var) {
	from += off[node];
	to += off[node];
	while (from < to) {
		if (from % 2) 
			add_implication(get_id(node, from++), 0, var, 1);
		if (to % 2) 
			add_implication(get_id(node, --to), 0, var, 1);
		from /= 2;
		to /= 2;
	}
}
 
void add_intersections(int x, int down, int up, int var) {
	for (x += offset; x; x /= 2) 
		if (off[x])
			update(x, get_bounds(x, down), get_bounds(x, up + 1), var);
}

void two_sat() {
	bool *sol = new bool[2 * n];
	char *bio = new char[2 * n];
	Graph adj(2 * n), rev(2 * n);
	for (int i = 0; i < e; i++) {
		adj.add(edges[i].first, edges[i].second);
		rev.add(edges[i].second, edges[i].first);
	}
	for (int i = 0; i < 2 * n; i++)
		if (!bio[i])
			dfs_forward(i, adj, bio);
	for (int i = 0; i < 2 * n; i++)
		bio[i] = 0;
	for (; !order.empty(); order.pop())
		if (!bio[order.top()])
			dfs_backward(order.top(), rev, bio, sol);
	puts("DA");
	for (auto it : segs)
		if (sol[2 * it.first])
			printf("%d %d\n", it.second.first + 1, it.second.second + 1);
	delete[] sol;
	delete[] bio;
}
 
void solve() {
	for (int i = 1; i < MAXN; i++) 
		if (hor[i].size() == 2) {
			int tmp = add_variables(1);
			segs[tmp] = {hor[i][0], hor[i][1]};
			int l = MAXN, r = 0;
			for (auto it : hor[i]) {
				graph[it].push_back(tmp);
				l = min(l, x[it]);
				r = max(r, x[it]);
			}
			insert(1, 0, offset, l, r + 1, tmp, i);
		}
	
	for (int i = 0; i < 2 * offset; i++)
		init(i);
	
	for (int i = 1; i < MAXN; i++) 
		if (ver[i].size() == 2) {
			int tmp = add_variables(1);
			segs[tmp] = {ver[i][0], ver[i][1]};
			int l = MAXN, r = 0;
			for (auto it : ver[i]) {
				graph[it].push_back(tmp);
				l = min(l, y[it]);
				r = max(r, y[it]);
			}
			add_intersections(i, l, r, tmp);
		}
	
	for (int i = 0; i < N; i++) 
		if (!graph[i].empty())
			add_implication(graph[i][0], 1, graph[i][1 % graph[i].size()], 0);
		else
			bye();
	
	two_sat();
}
 
int main() {
	double timer = clock();
	load();
	solve();
	fprintf(stderr, "%lf\n", (clock() - timer) / CLOCKS_PER_SEC);
	return 0;
}

Compilation message

matching.cpp: In function 'void add_clause(int, int, int)':
matching.cpp:119:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if (u < off[x] + tour[x].size())
      ~~^~~~~~~~~~~~~~~~~~~~~~~~~
matching.cpp: In function 'void init(int)':
matching.cpp:128:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while (off[x] < tour[x].size())
         ~~~~~~~^~~~~~~~~~~~~~~~
matching.cpp: In function 'void load()':
matching.cpp:94:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
matching.cpp:96:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", x + i, y + i);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 13824 KB Output is correct
2 Correct 14 ms 13824 KB Output is correct

Subtask #2
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 13824 KB Output is correct
2 Correct 14 ms 13824 KB Output is correct
3 Correct 12 ms 13824 KB Output is correct
4 Correct 13 ms 13824 KB Output is correct
5 Correct 12 ms 13824 KB Output is correct
6 Correct 12 ms 13824 KB Output is correct
7 Correct 14 ms 13824 KB Output is correct

Subtask #3
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 13824 KB Output is correct
2 Correct 14 ms 13824 KB Output is correct
3 Correct 12 ms 13824 KB Output is correct
4 Correct 13 ms 13824 KB Output is correct
5 Correct 12 ms 13824 KB Output is correct
6 Correct 12 ms 13824 KB Output is correct
7 Correct 14 ms 13824 KB Output is correct
8 Correct 13 ms 14080 KB Output is correct
9 Correct 15 ms 14080 KB Output is correct
10 Correct 13 ms 14080 KB Output is correct
11 Correct 13 ms 14080 KB Output is correct
12 Correct 14 ms 14080 KB Output is correct

Subtask #4
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 13824 KB Output is correct
2 Correct 14 ms 13824 KB Output is correct
3 Correct 12 ms 13824 KB Output is correct
4 Correct 13 ms 13824 KB Output is correct
5 Correct 12 ms 13824 KB Output is correct
6 Correct 12 ms 13824 KB Output is correct
7 Correct 14 ms 13824 KB Output is correct
8 Correct 13 ms 14080 KB Output is correct
9 Correct 15 ms 14080 KB Output is correct
10 Correct 13 ms 14080 KB Output is correct
11 Correct 13 ms 14080 KB Output is correct
12 Correct 14 ms 14080 KB Output is correct
13 Correct 23 ms 19072 KB Output is correct
14 Correct 23 ms 19072 KB Output is correct
15 Correct 27 ms 18944 KB Output is correct
16 Correct 27 ms 18944 KB Output is correct
17 Correct 22 ms 18944 KB Output is correct
18 Correct 22 ms 18944 KB Output is correct
19 Correct 22 ms 18944 KB Output is correct
20 Correct 28 ms 18944 KB Output is correct
21 Correct 22 ms 18944 KB Output is correct
22 Correct 21 ms 18944 KB Output is correct
23 Correct 32 ms 19584 KB Output is correct
24 Correct 23 ms 19712 KB Output is correct

Subtask #5
0 / 52.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 13824 KB Output is correct
2 Correct 14 ms 13824 KB Output is correct
3 Correct 12 ms 13824 KB Output is correct
4 Correct 13 ms 13824 KB Output is correct
5 Correct 12 ms 13824 KB Output is correct
6 Correct 12 ms 13824 KB Output is correct
7 Correct 14 ms 13824 KB Output is correct
8 Correct 13 ms 14080 KB Output is correct
9 Correct 15 ms 14080 KB Output is correct
10 Correct 13 ms 14080 KB Output is correct
11 Correct 13 ms 14080 KB Output is correct
12 Correct 14 ms 14080 KB Output is correct
13 Correct 23 ms 19072 KB Output is correct
14 Correct 23 ms 19072 KB Output is correct
15 Correct 27 ms 18944 KB Output is correct
16 Correct 27 ms 18944 KB Output is correct
17 Correct 22 ms 18944 KB Output is correct
18 Correct 22 ms 18944 KB Output is correct
19 Correct 22 ms 18944 KB Output is correct
20 Correct 28 ms 18944 KB Output is correct
21 Correct 22 ms 18944 KB Output is correct
22 Correct 21 ms 18944 KB Output is correct
23 Correct 32 ms 19584 KB Output is correct
24 Correct 23 ms 19712 KB Output is correct
25 Correct 763 ms 178516 KB Output is correct
26 Correct 735 ms 178528 KB Output is correct
27 Correct 714 ms 178532 KB Output is correct
28 Correct 722 ms 178880 KB Output is correct
29 Correct 539 ms 178312 KB Output is correct
30 Correct 668 ms 178312 KB Output is correct
31 Correct 511 ms 178568 KB Output is correct
32 Correct 525 ms 178212 KB Output is correct
33 Correct 507 ms 162508 KB Output is correct
34 Correct 576 ms 162556 KB Output is correct
35 Correct 161 ms 40068 KB Output is correct
36 Runtime error 799 ms 524292 KB Execution killed with signal 9 (could be triggered by violating memory limits)
37 Halted 0 ms 0 KB -