oj.uz

Submission #59099

# Submission time Handle Problem Language Result Execution time Memory
59099 2018-07-20T14:29:35 Z fallingstar Dancing Elephants (IOI11_elephants) C++14
100 / 100
 8551 ms 54456 KB 
#include "elephants.h"
#include <cassert>
#include <algorithm>
#include <vector>

using namespace std;

const int N = 1.5e5;

int n, L;

struct TElephant { 
	int id, x;
	int f, xDest;
	inline bool operator < (const TElephant &b) const 
	{
		return x < b.x || (x == b.x && id < b.id);			// if x equals, compare by id
	}
}; 

vector<vector<TElephant> > a;
int pos[N];

const int BLOCK_SIZE = 400;

void Calc(vector<TElephant> &seg)
{
	auto itR = prev(seg.end()), itL = itR;
	itL->f = 0, itL->xDest = itL->x;
	while (itL != seg.begin())
	{
		--itL;
		while (itR != itL && itL->x + L < prev(itR)->x) itR = prev(itR);
		if (itL->x + L < itR->x)
		{
			itL->f = itR->f + 1;
			itL->xDest = itR->xDest;
		}
		else 
			itL->f = 0, itL->xDest = itL->x;
	}
}

pair<int, int> arr[N];

void Rebuild()
{
	int m = 0;
	for (const auto &seg: a)
		for (const auto &e: seg)
			arr[m++] = {e.id, e.x};
	
	a.clear();
	vector<TElephant> cur;
	for (int i = 0; i < n; ++i)
	{
		cur.push_back({arr[i].first, arr[i].second, 0, arr[i].second});
		if (cur.size() >= BLOCK_SIZE || i == n - 1) 
		{
			Calc(cur);
			a.push_back(move(cur));
			cur.clear();
		}
	}
}

void init(int numElephants, int camWidth, int X[])
{
	n = numElephants;
	L = camWidth;
	vector<TElephant> sentinel;
	for (int i = 0; i < n; ++i) 
	{
		pos[i] = X[i];
		sentinel.push_back({i, X[i], 0, 0});
	}
	a.push_back(move(sentinel));
	Rebuild();
}

const int STACK_SIZE = 800;
int countQuery = 0;

int GetAns() 
{
	int ans = 0, curX = a.begin()->begin()->x;
	for (auto i = a.begin(); i != a.end(); ++i)
		if (prev(i->end())->x >= curX)					// if segment contain current X
		{
			for (auto it = i->begin(); it != i->end(); ++it)
				if (it->x >= curX)
				{
					ans += it->f + 1;					// jump inner-segment, then to new segment
					curX = it->xDest + L + 1;
					break;
				}
		}
	return ans;
}

int update(int idx, int y)
{
	int x = pos[idx];
	TElephant old_ele {idx, x, 0, 0};
	TElephant new_ele {idx, y, 0, 0};
	
	// erase idx from old position
	{
		auto i = lower_bound(a.begin(), a.end(), old_ele, [](const vector<TElephant> &p, TElephant q) {
			return p.back() < q;
		});
		vector<TElephant> leftSeg;
		for (auto it = i->begin(); it != i->end(); ++it)
			if (it->id == idx)
			{
				// cut segment into 2 parts
				leftSeg = vector<TElephant>(i->begin(), it);
				i->erase(i->begin(), next(it));
				break;
			}
		if (i->empty()) i = a.erase(i);
		if (!leftSeg.empty()) 
		{
			Calc(leftSeg);
			a.insert(i, move(leftSeg));
		}
	}
	
	// insert idx to new position
	if (a.empty()) 
		a.push_back(vector<TElephant>(1, new_ele)); 
	else
	{
		auto i = lower_bound(a.begin(), a.end(), new_ele, [](const vector<TElephant> &p, TElephant q) {
			return p.back() < q;
		});
		if (i != a.end())
		{
			for (auto it = i->begin(); it != i->end(); ++it)
				if (new_ele < *it)
				{
					i->insert(it, new_ele);
					break;
				}
		}
		else
		{
			--i;
			i->push_back(new_ele);
		}
		Calc(*i);
	}
	pos[idx] = y;
	++countQuery;
	if (countQuery >= STACK_SIZE) Rebuild(), countQuery = 0;
	return GetAns();
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 564 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 564 KB Output is correct
7 Correct 253 ms 1668 KB Output is correct
8 Correct 294 ms 1964 KB Output is correct
9 Correct 294 ms 3876 KB Output is correct
10 Correct 444 ms 3876 KB Output is correct
11 Correct 538 ms 3876 KB Output is correct
12 Correct 446 ms 4924 KB Output is correct
13 Correct 742 ms 4924 KB Output is correct

Subtask #4
47.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 564 KB Output is correct
7 Correct 253 ms 1668 KB Output is correct
8 Correct 294 ms 1964 KB Output is correct
9 Correct 294 ms 3876 KB Output is correct
10 Correct 444 ms 3876 KB Output is correct
11 Correct 538 ms 3876 KB Output is correct
12 Correct 446 ms 4924 KB Output is correct
13 Correct 742 ms 4924 KB Output is correct
14 Correct 293 ms 4924 KB Output is correct
15 Correct 323 ms 4924 KB Output is correct
16 Correct 737 ms 5304 KB Output is correct
17 Correct 897 ms 6256 KB Output is correct
18 Correct 1053 ms 6276 KB Output is correct
19 Correct 538 ms 6276 KB Output is correct
20 Correct 863 ms 6276 KB Output is correct
21 Correct 885 ms 6276 KB Output is correct
22 Correct 1404 ms 6276 KB Output is correct

Subtask #5
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 564 KB Output is correct
7 Correct 253 ms 1668 KB Output is correct
8 Correct 294 ms 1964 KB Output is correct
9 Correct 294 ms 3876 KB Output is correct
10 Correct 444 ms 3876 KB Output is correct
11 Correct 538 ms 3876 KB Output is correct
12 Correct 446 ms 4924 KB Output is correct
13 Correct 742 ms 4924 KB Output is correct
14 Correct 293 ms 4924 KB Output is correct
15 Correct 323 ms 4924 KB Output is correct
16 Correct 737 ms 5304 KB Output is correct
17 Correct 897 ms 6256 KB Output is correct
18 Correct 1053 ms 6276 KB Output is correct
19 Correct 538 ms 6276 KB Output is correct
20 Correct 863 ms 6276 KB Output is correct
21 Correct 885 ms 6276 KB Output is correct
22 Correct 1404 ms 6276 KB Output is correct
23 Correct 2713 ms 9916 KB Output is correct
24 Correct 2735 ms 10136 KB Output is correct
25 Correct 1631 ms 10136 KB Output is correct
26 Correct 1906 ms 10136 KB Output is correct
27 Correct 1671 ms 10136 KB Output is correct
28 Correct 805 ms 10136 KB Output is correct
29 Correct 715 ms 10136 KB Output is correct
30 Correct 853 ms 10136 KB Output is correct
31 Correct 781 ms 10136 KB Output is correct
32 Correct 3817 ms 10136 KB Output is correct
33 Correct 1507 ms 11724 KB Output is correct
34 Correct 3928 ms 16488 KB Output is correct
35 Correct 1268 ms 21240 KB Output is correct
36 Correct 1474 ms 27736 KB Output is correct
37 Correct 2687 ms 32996 KB Output is correct
38 Correct 6736 ms 34300 KB Output is correct
39 Correct 2126 ms 39040 KB Output is correct
40 Correct 8551 ms 42592 KB Output is correct
41 Correct 3039 ms 49920 KB Output is correct
42 Correct 3412 ms 54456 KB Output is correct