Submission #427412

#	Time	Username	Problem	Language	Result	Execution time	Memory
427412		pavement	Port Facility (JOI17_port_facility)	C++17	0 / 100	4 ms	460 KiB

port_facility

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
//#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef double db;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
 
int N, ans, lft[2000005], rig[2000005], L[2000005], R[2000005], link[2000005], sz[2000005], r[2000005];
bool inv, col[2000005], vis[2000005], cl[2000005];
vector<ii> curr;
set<int> seg;
const int MOD = 1e9 + 7;

void read(int &v) {
	v = 0;
	char ch = getchar_unlocked();
	for (; ch < '0' || ch > '9'; ch = getchar_unlocked());
	for (; '0' <= ch && ch <= '9'; ch = getchar_unlocked())
		v = (v << 3) + (v << 1) + (ch & 15);
}
 
bool is(int a, int b) {
	if (L[a] > L[b]) return is(b, a);
	return R[b] > R[a] && R[a] > L[b];
}
 
int find(int x) {
	if (x == link[x]) return x;
	return link[x] = find(link[x]);
}
 
void unite(int a, int b) {
	a = find(a);
	b = find(b);
	if (a == b) return;
	if (sz[b] > sz[a]) swap(a, b);
	sz[a] += sz[b];
	link[b] = a;
}
 
void go(int n);
 
struct node {
	node *left, *right;
	list<int> val;
	node(int S, int E) {
		if (S == E) return;
		int M = (S + E) >> 1;
		left = new node(S, M);
		right = new node(M + 1, E);
	}
	void upd(int S, int E, int p, int idx) {
		val.pb(idx);
		if (S == E) return;
		int M = (S + E) >> 1;
		if (p <= M) left->upd(S, M, p, idx);
		else right->upd(M + 1, E, p, idx);
	}
	void getall(int S, int E, int l, int r, int curr) {
		if (l > E || r < S) return;
		if (l <= S && E <= r) {
			while (!val.empty() && R[val.back()] > r) {
				if (!vis[val.back()]) col[val.back()] = col[curr] ^ 1, go(val.back());
				else if (col[val.back()] == col[curr]) inv = 1;
				val.ppb();
			}
			return;
		}
		int M = (S + E) >> 1;
		left->getall(S, M, l, r, curr);
		right->getall(M + 1, E, l, r, curr);
	}
} *root;
 
struct node2 {
	node2 *left, *right;
	list<int> val;
	node2(int S, int E) {
		if (S == E) return;
		int M = (S + E) >> 1;
		left = new node2(S, M);
		right = new node2(M + 1, E);
	}
	void upd(int S, int E, int p, int idx) {
		val.pb(idx);
		if (S == E) return;
		int M = (S + E) >> 1;
		if (p <= M) left->upd(S, M, p, idx);
		else right->upd(M + 1, E, p, idx);
	}
	void getall(int S, int E, int l, int r, int curr) {
		if (l > E || r < S) return;
		if (l <= S && E <= r) {
			while (!val.empty() && L[val.back()] < l) {
				if (!vis[val.back()]) col[val.back()] = col[curr] ^ 1, go(val.back());
				else if (col[val.back()] == col[curr]) inv = 1;
				val.ppb();
			}
			return;
		}
		int M = (S + E) >> 1;
		left->getall(S, M, l, r, curr);
		right->getall(M + 1, E, l, r, curr);
	}
} *root2;
 
void go(int n) {
	vis[n] = 1;
	root->getall(1, 2 * N, L[n], R[n], n);
	root2->getall(1, 2 * N, L[n], R[n], n);
}
 
main() {
	read(N);
	root = new node(1, 2 * N);
	root2 = new node2(1, 2 * N);
	for (int i = 1; i <= N; i++) {
		link[i] = i;
		sz[i] = 1;
		read(L[i]);
		read(R[i]);
		cl[R[i]] = 1;
		r[L[i]] = r[R[i]] = i;
	}
	for (int i = 1; i <= 2 * N; i++)
		if (cl[i]) root->upd(1, 2 * N, L[r[i]], r[i]);
	for (int i = 2 * N; i >= 1; i--)
		if (!cl[i]) root2->upd(1, 2 * N, R[r[i]], r[i]);
	ans = 1;
	for (int i = 1; i <= N; i++)
		if (!vis[i]) go(i), ans *= 2, ans %= MOD;
	if (inv) return puts("0"), 0;
	printf("%d\n", ans);
	//~ for (int i = 1; i <= 2 * N; i++) {
		//~ if (cl[i]) {
			//~ int pos = -1, cnt = 0;
			//~ for (int j = (int)curr.size() - 1; j >= 0; j--) {
				//~ if (find(r[i]) == find(curr[j].first)) {
					//~ pos = j;
					//~ break;
				//~ } else unite(r[i], curr[j].first), cnt += curr[j].second;
			//~ }
			//~ if (pos == -1) while (1) {}
			//~ for (int k = 0, run = curr.size() - pos; k < run - 1; k++) curr.ppb();
			//~ curr.back().second += cnt - 1;
			//~ if (curr.back().second == 0) curr.ppb();
		//~ } else {
			//~ curr.eb(r[i], 1);
		//~ }
	//~ }
	//~ ans = 1;
	//~ for (int i = 1; i <= N; i++)
		//~ if (i == find(i)) ans *= 2, ans %= MOD;
	//~ printf("%d\n", ans);
}

Compilation message (stderr)

port_facility.cpp:133:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  133 | main() {
      | ^~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22