Submission #770910

#	Time	Username	Problem	Language	Result	Execution time	Memory
770910		SanguineChameleon	Comparing Plants (IOI20_plants)	C++17	5 / 100	65 ms	6524 KiB

plants

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

const int maxn = 2e5 + 20;
const int inf = 1e9 + 20;
int a[maxn];
int tree[maxn * 4];
int lazy[maxn * 4];
int pos[maxn];
int dp_left[maxn];
int dp_right[maxn];
int n, k;
set<int> all_zeroes, good_zeroes;

void build(int id, int lt, int rt) {
	if (lt == rt) {
		tree[id] = a[lt];
		return;
	}
	int mt = (lt + rt) / 2;
	build(id * 2, lt, mt);
	build(id * 2 + 1, mt + 1, rt);
	tree[id] = min(tree[id * 2], tree[id * 2 + 1]);
}

void update(int id, int lt, int rt, int ql, int qr, int add) {
	if (lt == ql && rt == qr) {
		tree[id] += add;
		lazy[id] += add;
		return;
	}
	tree[id * 2] += lazy[id];
	lazy[id * 2] += lazy[id];
	tree[id * 2 + 1] += lazy[id];
	lazy[id * 2 + 1] += lazy[id];
	lazy[id] = 0;
	int mt = (lt + rt) / 2;
	if (qr <= mt) {
		update(id * 2, lt, mt, ql, qr, add);
	}
	else if (ql >= mt + 1) {
		update(id * 2 + 1, mt + 1, rt, ql, qr, add);
	}
	else {
		update(id * 2, lt, mt, ql, mt, add);
		update(id * 2 + 1, mt + 1, rt, mt + 1, qr, add);
	}
	tree[id] = min(tree[id * 2], tree[id * 2 + 1]);
}

bool contains(int x, int y) {
	if (x < y) {
		return y - x + 1 <= k;
	}
	else {
		return n - (x - y - 1) <= k;
	}
}

void add_zero(int x) {
	auto it = all_zeroes.insert(x).first;
	int prv = (it == all_zeroes.begin() ? *all_zeroes.rbegin() : *prev(it));
	if (!contains(prv, x)) {
		good_zeroes.insert(x);
	} 
	int nxt = (next(it) == all_zeroes.end() ? *all_zeroes.begin() : *next(it));
	if (contains(x, nxt)) {
		assert(false);
		good_zeroes.erase(nxt);
	}
	else {
		good_zeroes.insert(nxt);
	}
}

void rem_zero(int x) {
	auto it = all_zeroes.find(x);
	int prv = (it == all_zeroes.begin() ? *all_zeroes.rbegin() : *prev(it));
	int nxt = (next(it) == all_zeroes.end() ? *all_zeroes.begin() : *next(it));
	if (contains(prv, nxt)) {
		good_zeroes.erase(nxt);
	}
	else {
		good_zeroes.insert(nxt);
	}
	int rt = x;
	int lt = (rt + n - (k - 1)) % n;
	if (lt <= rt) {
		update(1, 0, n - 1, lt, rt, -1);
	}
	else {
		update(1, 0, n - 1, lt, n - 1, -1);
		update(1, 0, n - 1, 0, rt, -1);
	}
	all_zeroes.erase(it);
	good_zeroes.erase(x);
}

void find_zeroes(int id, int lt, int rt) {
	if (tree[id] > 0) {
		return;
	}
	if (lt == rt) {
		add_zero(lt);
		tree[id] = inf;
		lazy[id] = 0;
		return;
	}
	tree[id * 2] += lazy[id];
	lazy[id * 2] += lazy[id];
	tree[id * 2 + 1] += lazy[id];
	lazy[id * 2 + 1] += lazy[id];
	lazy[id] = 0;
	int mt = (lt + rt) / 2;
	find_zeroes(id * 2, lt, mt);
	find_zeroes(id * 2 + 1, mt + 1, rt);
	tree[id] = min(tree[id * 2], tree[id * 2 + 1]);
}

void init(int _k, vector<int> _a) {
	n = _a.size();
	k = _k;
	for (int i = 0; i < n; i++) {
		a[i] = k - 1 - _a[i];
	}
	if (k == 2) {
		for (int i = 0; i < n; i++) {
			if (a[i] == 0) {
				dp_right[i] = i;
				for (int j = (i + n - 1) % n; j != i; j = (j + n - 1) % n) {
					dp_right[j] = (a[j] ? dp_right[(j + 1) % n] : j);
				}
				break;
			}
		}
		for (int i = 0; i < n; i++) {
			if (a[(i + n - 1) % n] == 1) {
				dp_left[i] = i;
				for (int j = (i + 1) % n; j != i; j = (j + 1) % n) {
					dp_left[j] = (!a[(j + n - 1) % n] ? dp_left[(j + n - 1) % n] : j);
				}
				break;
			}
		}
	}
	else {
		build(1, 0, n - 1);
		for (int i = 0; i < n; i++) {
			find_zeroes(1, 0, n - 1);
			pos[*good_zeroes.begin()] = i;
			rem_zero(*good_zeroes.begin());
		}
	}
	return;
}

bool check(int x, int y) {
	if (dp_left[x] == dp_right[x]) {
		return (dp_left[x] != x);
	}
	else if (dp_left[x] < dp_right[x]) {
		return dp_left[x] <= y && y <= dp_right[x];
	}
	else {
		return (y >= dp_left[x] || y <= dp_right[x]);
	}
}

int compare_plants(int x, int y) {
	if (k == 2) {
		if (check(x, y)) {
			return 1;
		}
		else if (check(y, x)) {
			return -1;
		}
		else {
			return 0;
		}
	}
	else {
		return (pos[x] > pos[y] ? 1 : -1);
	}
}

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