Submission #1244584

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244584		Joshua_Andersson	Comparing Plants (IOI20_plants)	C++20	25 / 100	4096 ms	28096 KiB

plants

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const ll inf = 1e18;

typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> p2;

#define rep(i, high) for (ll i = 0; i < (high); i++)
#define repp(i, lo, high) for (ll i = (lo); i < (high); i++)
#define repe(i, container) for (auto& i : container)
#define sz(x) ((ll)(x).size())
#define all(x) begin(x), end(x)

struct Tree
{
	vector<p2> tree;
	vi lazy;
	Tree(int n) : tree(n*4), lazy(n*4) {}

	p2 merge(p2 a, p2 b)
	{
		if (a.first <= b.first) return a;
		return b;
	}

	void push(int x)
	{
		tree[x * 2].first += lazy[x];
		lazy[x * 2] += lazy[x];
		tree[x * 2+1].first += lazy[x];
		lazy[x * 2 + 1] += lazy[x];
		lazy[x] = 0;
	}

	void set(int x, int l, int r, int i, ll v)
	{
		if (l == r) return void(tree[x] = p2(v, l));
		push(x);
		int mid = (l + r) / 2;
		if (i <= mid) set(x * 2, l, mid, i, v);
		else set(x * 2 + 1, mid + 1, r, i, v);
		tree[x] = merge(tree[x * 2], tree[x * 2 + 1]);
	}

	p2 query(int x, int l, int r, int ql, int qr)
	{
		if (r<ql || l>qr) return p2(inf, 0);
		if (l >= ql && r <= qr) return tree[x];
		push(x);
		int mid = (l + r) / 2;
		return merge(query(x * 2, l, mid, ql, qr), query(x * 2 + 1, mid + 1, r, ql, qr));
	}

	void add(int x, int l, int r, int ql, int qr, ll amount)
	{
		if (r<ql || l>qr) return;
		if (l >= ql && r <= qr)
		{
			tree[x].first += amount;
			lazy[x] += amount;
			return;
		}
		push(x);
		int mid = (l + r) / 2;
		add(x * 2, l, mid, ql, qr, amount);
		add(x * 2 + 1, mid + 1, r, ql, qr, amount);
		tree[x] = merge(tree[x * 2], tree[x * 2 + 1]);
	}
};

int n,k;
vi ljump;
vi rjump;
vi real_heights;
void init(int K, std::vector<int> r) {
	k = K;
	n = sz(r);
	real_heights.resize(n);
	rjump.resize(n, -1);
	ljump.resize(n, -1);


	auto norm = [&](int x)
		{
			if (x < 0) x %= n, x += n;
			if (x >= n) return x % n;
			return x;
		};

	Tree tree(n);

	rep(i, n) tree.set(1, 0, n - 1, i, r[i]);

	auto find_zero = [&](int ql, int qr)
		{
			ql = norm(ql); qr = norm(qr);
			p2 q;
			if (ql <= qr) q = tree.query(1, 0, n - 1, ql, qr);
			else q = tree.merge(tree.query(1, 0, n - 1, 0, qr), tree.query(1, 0, n - 1, ql, n - 1));
			if (q.first == 0) return q.second;
			return -1LL;
		};

	auto decrease = [&](int ql, int qr)
		{
			ql = norm(ql); qr = norm(qr);
			if (ql <= qr) tree.add(1, 0, n - 1, ql, qr, -1);
			else tree.add(1, 0, n - 1, 0, qr, -1), tree.add(1, 0, n - 1, ql, n - 1, -1);
		};

	ll ind = n - 1;
	rep(i, n)
	{
		ll j = find_zero(0, n-1);
		if (j == -1) break;
		vi st = { j };
		while (sz(st))
		{
			ll u = st.back();
			ll v = find_zero(u - k + 1, u - 1);
			if (v == -1)
			{
				st.pop_back();
				real_heights[u] = ind--;
				decrease(u - k + 1, u - 1);
				tree.set(1, 0, n - 1, u, inf);
			}
			else
			{
				st.push_back(v);
			}
		}
	}


	rep(i, n)
	{
		p2 best = p2(-1, -1);
		repp(j, i + 1, i + k)
		{
			if (real_heights[norm(j)] < real_heights[i])
			{
				best = max(best, p2(real_heights[norm(j)], norm(j)));
			}
		}
		if (best.second != -1) rjump[i] = best.second;
		best = p2(-1, -1);
		repp(j, 1, k)
		{
			if (real_heights[norm(i-j)]<real_heights[i])
			{
				best = max(best, p2(real_heights[norm(i-j)], norm(i-j)));
			}
		}
		if (best.second != -1) ljump[i] = best.second;
	}

	return;
}

int dist(int a, int b)
{
	return min(abs(a - b), min(abs(a + n - b), abs(b + n - a)));
}

map<p2, int> cache;
int reachable(int a, int b)
{
	p2 s = p2(a, b);
	if (cache.count(s)) return cache[s];
	// first, try CW

	int x = a;
	while (dist(x,b)>=k && rjump[x]!=-1)
	{
		x = rjump[x];
	}
	if (dist(x,b)<k && real_heights[x] > real_heights[b]) return true;

	x = a;

	while (dist(x, b)>=k && ljump[x]!=-1)
	{
		x = ljump[x];
	}
	if (dist(x, b) < k && real_heights[x]>real_heights[b]) return true;
	return false;
}


int compare_plants(int x, int y) {
	if (reachable(x, y)) return 1;
	if (reachable(y, x)) return -1;
	return 0;
}

#if _LOCAL

static int q;
static std::vector<int> r;
static std::vector<int> x;
static std::vector<int> y;
static std::vector<int> answer;
int main() {
	int n,k;
	assert(scanf("%d%d%d", &n, &k, &q) == 3);
	r.resize(n);
	answer.resize(q);
	for (int i = 0; i < n; i++) {
		int value;
		assert(scanf("%d", &value) == 1);
		r[i] = value;
	}
	x.resize(q);
	y.resize(q);
	for (int i = 0; i < q; i++) {
		assert(scanf("%d%d", &x[i], &y[i]) == 2);
	}
	fclose(stdin);

	init(k, r);
	for (int i = 0; i < q; i++) {
		answer[i] = compare_plants(x[i], y[i]);
	}

	for (int i = 0; i < q; i++) {
		printf("%d\n", answer[i]);
	}

	fclose(stdout);

	return 0;
}
#endif

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 11 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25