Submission #311663

#	Time	Username	Problem	Language	Result	Execution time	Memory
311663		tfg	Comparing Plants (IOI20_plants)	C++17	0 / 100	56 ms	5368 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(2*n, 0);
		lazy.assign(2*n, 0);
		for(int i = 0; i < n; i++) {
			tree[n+i] = a[i];
		}
		for(int i = n-1; i > 0; i--) {
			tree[i] = std::min(tree[i+i], tree[i+i+1]);
		}
	}

	void upd(int l, int r, int v) {
		if(l >= r) {
			return;
		}
		while(l >= n) {
			l -= n;
			r -= n;
		}
		while(l < 0) {
			l += n;
			r += n;
		}
		//std::cout << "update [" << l << ", " << r << "), v is " << v << std::endl;
		if(r > n) {
			upd(0, r - n, v);
			r = n;
		}
		l += n, r += n;
		int l0 = l, r0 = r;
		push(l / 2);
		push((r-1) / 2);
		for(; l < r; l /= 2, r /= 2) {
			if(l & 1) lazy[l++] += v;
			if(r & 1) lazy[--r] += v;
		}
		up(l0);
		up(r0-1);
	}

	int qry(int l, int r) {
		if(l >= r) return INF;
		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));
		}
		//std::cout << "query [" << l << ", " << r << ")" << std::endl;
		int ans = INF;
		l += n, r += n;
		push(l / 2);
		push((r-1) / 2);
		for(; l < r; l /= 2, r /= 2) {
			if(l & 1) ans = std::min(ans, tree[l++]);
			if(r & 1) ans = std::min(ans, tree[--r]);
		}
		//std::cout << "answer is " << ans << '\n';
		return ans;
	}

	void push(int x) {
		if(x != 1) push(x / 2);
		if(x+x < n) {
			lazy[x+x] += lazy[x];
		}
		if(x+x+1 < n) {
			lazy[x+x+1] += lazy[x];
		}
		tree[x+x] += lazy[x];
		tree[x+x+1] += lazy[x];
		lazy[x] = 0;
	}

	void up(int x) {
		if(x >= n) {
			tree[x] += lazy[x];
			lazy[x] = 0;
		}
		tree[x/2] = std::min(tree[x], tree[x^1]) + lazy[x/2];
		if(x/2 > 1) {
			up(x/2);
		}
	}

	int n;
	std::vector<int> tree, lazy;
};

/*struct SegTree {
	void init(std::vector<int> a) {
		tree = a;
		n = (int) a.size();
	}

	void upd(int l, int r, int v) {
		for(int i = l; i < r; i++) {
			tree[(i%n+n)%n] += v;
		}
	}

	int qry(int l, int r) {
		int ans = INF;
		for(int i = l; i < r; i++) {
			ans = std::min(ans, tree[(i%n+n)%n]);
		}
		return ans;
	}
	int n;
	std::vector<int> tree;
};*/

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; }

void solve(std::vector<int> r, int k, int bit, int ans[ms], int rep) {
	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)) {
			//std::cout << "got " << i << std::endl;
			kek[i] = true;
			hp.push({((i >> bit) & 1) ^ rep, i});
		}
	}
	int id = 0;
	while(!hp.empty()) {
		int on = hp.top().second;
		//std::cout << "taking " << on << std::endl;
		hp.pop();
		tree.upd(on, on+1, INF);
		assert(tree.qry(on-k+1, on) != 0);
		tree.upd(on-k+1, on, -1);
		/*for(int i = 0; i < n; i++) {
			std::cout << tree.qry(i, i+1) << (i + 1 == n ? '\n' : ' ');
		}*/
		int l1 = leftmost(on-k+1, on);
		int l2 = leftmost(on+1, on+k);
		l1 = (l1 % n + n) % n;
		l2 = (l2 % n + n) % n;
		//std::cout << "testing " << l1 << " and " << l2 << '\n';
		if(!kek[l1] && test(l1, k)) {
			//std::cout << "got " << l1 << '\n';
			kek[l1] = true;
			hp.push({((l1 >> bit) & 1) ^ rep, l1});
		}
		if(!kek[l2] && test(l2, k)) {
			//std::cout << "got " << l2 << '\n';
			kek[l2] = true;
			hp.push({((l2 >> bit) & 1) ^ rep, l2});
		}
		ans[on] = id++;
	}
	assert(id == n);
}

void init(int k, std::vector<int> r) {
	for(int bit = 0; bit < me; bit++) {
		//std::cout << "solving for bit " << bit << std::endl;
		for(int rep = 0; rep < 2; rep++) {
			solve(r, k, bit, pos[bit][rep], rep);
		}
	}
	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 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, getBit(x^y));
}

• Subtask 1: 0 / 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