제출 #65959

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
65959		aome	Flood (IOI07_flood)	C++17	57 / 100	185 ms	22212 KiB

flood

#include <bits/stdc++.h>

using namespace std;

const int N = 100005;

int n, m;
int e[N][4];
int it[N << 2];
int T, st[N], ed[N];
int p[N], h[N], par[N];
int fr[N * 2], to[N * 2];
bool visit[N], del[N * 2];
pair<int, int> a[N];
vector<int> vec;

void add(int u, int v, int id) {
	if (a[u].first == a[v].first) {
		if (a[u].second < a[v].second) e[u][1] = id; else e[u][3] = id;
	}
	else {
		if (a[u].first < a[v].first) e[u][2] = id; else e[u][0] = id;
	}
}

void dfs(int u, int x) {
	visit[u] = 1, x = (x + 3) % 4;
	st[u] = ++T;
	for (int i = 0; i < 4; ++i) {
		int y = (x + i) % 4;
		int id = e[u][y];
		if (!id) continue;
		int v = fr[id] ^ to[id] ^ u;
		if (par[u] == id) continue;
		if (visit[v]) {
			if (h[u] > h[v]) vec.push_back(id);
			continue;
		}
		par[v] = id, h[v] = h[u] + 1, dfs(v, y);
	}
	ed[u] = T;
}

void push(int i, int l, int r) {
	if (l != r) {
		it[i << 1] += it[i], it[i << 1 | 1] += it[i];
		it[i] = 0;
	}
}

void upd(int i, int l, int r, int L, int R) {
	push(i, l, r);
	if (l > R || L > r) return;
	if (L <= l && r <= R) {
		it[i]++, push(i, l, r); return;
	}
	int mid = (l + r) >> 1;
	upd(i << 1, l, mid, L, R);
	upd(i << 1 | 1, mid + 1, r, L, R);
}

int get(int i, int l, int r, int p) {
	push(i, l, r);
	if (l == r) return it[i];
	int mid = (l + r) >> 1;
	if (mid >= p) return get(i << 1, l, mid, p);
	else return get(i << 1 | 1, mid + 1, r, p);
}

int main() {
	ios::sync_with_stdio(false);
	cin >> n;
	for (int i = 1; i <= n; ++i) {
		p[i] = i;
		cin >> a[i].first >> a[i].second;
	}
	cin >> m;
	for (int i = 1; i <= m; ++i) {
		cin >> fr[i] >> to[i];
		add(fr[i], to[i], i), add(to[i], fr[i], i);
	}
	sort(p + 1, p + 1 + n, [&] (int x, int y) {
		return a[x] < a[y];
	});
	for (int i = 1; i <= n; ++i) {
		if (visit[p[i]]) continue;
		dfs(p[i], 2);
		for (auto j : vec) {
			int u = fr[j], v = to[j];
			if (h[u] < h[v]) swap(u, v);
			int fu = get(1, 1, n, st[u]);
			int fv = get(1, 1, n, st[v]);
			if (fu - fv) continue;
			del[j] = 1;
			while (u != v) {
				int id = par[u];
				upd(1, 1, n, st[u], ed[u]);
				del[id] = 1, u = fr[id] ^ to[id] ^ u;
			}
		}
		vec.clear();
	}
	int res = 0;
	for (int i = 1; i <= m; ++i) if (!del[i]) ++res;
	cout << res << '\n';
	for (int i = 1; i <= m; ++i) if (!del[i]) cout << i << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 3
• Subtask 5: 10 / 10
• Subtask 6: 3 / 3
• Subtask 7: 3 / 3
• Subtask 8: 3 / 3
• Subtask 9: 0 / 3
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9
• Subtask 12: 0 / 9
• Subtask 13: 0 / 9
• Subtask 14: 0 / 9