Submission #311677

#	Time	Username	Problem	Language	Result	Execution time	Memory
311677		tfg	Comparing Plants (IOI20_plants)	C++17	44 / 100	3018 ms	12292 KiB

plants

#include "plants.h"
#include <vector>
#include <queue>
#include <cassert>
#include <iostream>

const int INF = 1e9;

struct SegTree {
	void init(std::vector<int> &a) {
		n = (int) a.size();
		tree.assign(4*n, 0);
		lazy.assign(4*n, 0);
		build(1, 0, n, a);
	}

	void build(int id, int l, int r, std::vector<int> &a) {
		if(l + 1 == r) {
			tree[id] = a[l];
		} else {
			int mid = (l + r) / 2;
			build(id+id, l, mid, a);
			build(id+id+1, mid, r, a);
			tree[id] = std::min(tree[id+id], tree[id+id+1]);
		}
	}

	int qry(int l, int r) {
		while(l >= n) {
			l -= n;
			r -= n;
		}
		while(l < 0) {
			l += n;
			r += n;
		}
		if(r > n) {
			return std::min(qry(l, n), qry(0, r-n));
		}
		return qry(1, 0, n, l, r);
	}

	int qry(int id, int l, int r, int i, int j) {
		//std::cout << "qry (" << id << ", " << l << ", " << r << ", " << i << ", " << j << ")\n";
		if(l >= r || r <= i || l >= j) return INF;
		if(i <= l && r <= j) return tree[id];
		int mid = (l + r) / 2;
		push(id);
		return std::min(qry(id+id, l, mid, i, j), qry(id+id+1, mid, r, i, j));
	}

	void upd(int l, int r, int v) {
		while(l >= n) {
			l -= n;
			r -= n;
		}
		while(l < 0) {
			l += n;
			r += n;
		}
		if(r > n) {
			upd(l, n, v);
			upd(0, r-n, v);
		} else {
			upd(1, 0, n, l, r, v);
		}
	}

	void upd(int id, int l, int r, int i, int j, int v) {
		if(l >= r || r <= i || l >= j) return;
		if(i <= l && r <= j) {
			tree[id] += v;
			lazy[id] += v;
			return;
		}
		int mid = (l + r) / 2;
		push(id);
		upd(id+id, l, mid, i, j, v);
		upd(id+id+1, mid, r, i, j, v);
		tree[id] = std::min(tree[id+id], tree[id+id+1]);
	}

	void push(int id) {
		if(lazy[id]) {
			//assert(id+id+1 < 4*n);
			lazy[id+id] += lazy[id];
			lazy[id+id+1] += lazy[id];
			tree[id+id] += lazy[id];
			tree[id+id+1] += lazy[id];
			lazy[id] = 0;
		}
	}
	int n;
	std::vector<int> tree, lazy;
};

const int me = 18;
const int ms = 1 << me;
SegTree tree;
int pos[me][2][ms];
int leftmost(int l, int r) {
	if(l+1 >= r) return l;
	int mid = l + (r - l) / 2;
	if(tree.qry(l, mid) == 0) return leftmost(l, mid);
	else return leftmost(mid, r);
}

int rightmost(int l, int r) {
	if(l+1 >= r) return l;
	int mid = l + (r - l) / 2;
	if(tree.qry(mid, r) == 0) return rightmost(mid, r);
	else return rightmost(l, mid);
}

bool test(int i, int k) { return tree.qry(i, i+1) == 0 && tree.qry(i-k+1, i) != 0; }

template<const int rep>
void solve(std::vector<int> r, int k, int bit, int ans[ms]) {
	int n = (int) r.size();
	std::priority_queue<std::pair<int, int>> hp;
	tree.init(r);
	std::vector<bool> kek(n, false);
	for(int i = 0; i < n; i++) {
		if(test(i, k)) {
			kek[i] = true;
			hp.push({(((i >> bit) & 1) ^ rep) * 1001000 + (rep == 0 ? i : -i), i});
		}
	}
	int id = 0;
	while(!hp.empty() && id != n) {
		int on = hp.top().second;
		hp.pop();
		tree.upd(on, on+1, INF);
		assert(tree.qry(on-k+1, on) != 0);
		tree.upd(on-k+1, on, -1);
		int l1 = leftmost(on-k+1, on);
		int l2 = leftmost(on+1, on+k);
		l1 = (l1 % n + n) % n;
		l2 = (l2 % n + n) % n;
		if(!kek[l1] && test(l1, k)) {
			kek[l1] = true;
			hp.push({(((l1 >> bit) & 1) ^ rep) * 1001000 + (rep == 0 ? l1 : -l1), l1});
		}
		if(!kek[l2] && test(l2, k)) {
			kek[l2] = true;
			hp.push({(((l2 >> bit) & 1) ^ rep) * 1001000 + (rep == 0 ? l2 : -l2), l2});
		}
		ans[on] = id++;
	}
	assert(id == n);
}

void init(int k, std::vector<int> r) {
	for(int bit = 0; bit < 1; bit++) {
		//std::cout << "solving for bit " << bit << std::endl;
		solve<0>(r, k, bit, pos[bit][0]);
		//solve<1>(r, k, bit, pos[bit][1]);
	}
	return;
}

int getAnswer(int x, int y, int bit) {
	int b1 = pos[bit][0][x] < pos[bit][0][y];
	//int b2 = pos[bit][1][x] < pos[bit][1][y];
	int b2 = b1;
	int wot = b1 + 2 * b2;
	if(wot == 3) {
		return 1;
	} else if(wot == 0) {
		return -1;
	} else {
		return 0;
	}
}

int getBit(int x) { return (x & 1) ? 0 : 1 + getBit(x / 2); }

int compare_plants(int x, int y) {
	return getAnswer(x, y, 0);
}

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