oj.uz

Submission #59112

# Submission time Handle Problem Language Result Execution time Memory
59112 2018-07-20T14:48:47 Z fallingstar Dancing Elephants (IOI11_elephants) C++14
100 / 100
 5554 ms 10800 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 = 800;

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 = 400;
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
		{
			auto it = lower_bound(i->begin(), i->end(), curX, [](TElephant p, int q) { 
				return p.x < q;
			});
			ans += it->f + 1;					// jump inner-segment, then to new segment
			curX = it->xDest + L + 1;	
		}
	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 3 ms 488 KB Output is correct
5 Correct 3 ms 488 KB Output is correct
6 Correct 2 ms 504 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 3 ms 488 KB Output is correct
5 Correct 3 ms 488 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 343 ms 1744 KB Output is correct
8 Correct 323 ms 1952 KB Output is correct
9 Correct 410 ms 3984 KB Output is correct
10 Correct 417 ms 3984 KB Output is correct
11 Correct 357 ms 3984 KB Output is correct
12 Correct 740 ms 4904 KB Output is correct
13 Correct 332 ms 4904 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 3 ms 488 KB Output is correct
5 Correct 3 ms 488 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 343 ms 1744 KB Output is correct
8 Correct 323 ms 1952 KB Output is correct
9 Correct 410 ms 3984 KB Output is correct
10 Correct 417 ms 3984 KB Output is correct
11 Correct 357 ms 3984 KB Output is correct
12 Correct 740 ms 4904 KB Output is correct
13 Correct 332 ms 4904 KB Output is correct
14 Correct 398 ms 4904 KB Output is correct
15 Correct 347 ms 4904 KB Output is correct
16 Correct 1244 ms 5312 KB Output is correct
17 Correct 1496 ms 6272 KB Output is correct
18 Correct 1648 ms 6272 KB Output is correct
19 Correct 871 ms 6272 KB Output is correct
20 Correct 1577 ms 6272 KB Output is correct
21 Correct 1469 ms 6356 KB Output is correct
22 Correct 633 ms 6356 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 3 ms 488 KB Output is correct
5 Correct 3 ms 488 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 343 ms 1744 KB Output is correct
8 Correct 323 ms 1952 KB Output is correct
9 Correct 410 ms 3984 KB Output is correct
10 Correct 417 ms 3984 KB Output is correct
11 Correct 357 ms 3984 KB Output is correct
12 Correct 740 ms 4904 KB Output is correct
13 Correct 332 ms 4904 KB Output is correct
14 Correct 398 ms 4904 KB Output is correct
15 Correct 347 ms 4904 KB Output is correct
16 Correct 1244 ms 5312 KB Output is correct
17 Correct 1496 ms 6272 KB Output is correct
18 Correct 1648 ms 6272 KB Output is correct
19 Correct 871 ms 6272 KB Output is correct
20 Correct 1577 ms 6272 KB Output is correct
21 Correct 1469 ms 6356 KB Output is correct
22 Correct 633 ms 6356 KB Output is correct
23 Correct 4112 ms 9824 KB Output is correct
24 Correct 4763 ms 10268 KB Output is correct
25 Correct 3410 ms 10268 KB Output is correct
26 Correct 2583 ms 10268 KB Output is correct
27 Correct 2860 ms 10268 KB Output is correct
28 Correct 851 ms 10268 KB Output is correct
29 Correct 688 ms 10268 KB Output is correct
30 Correct 694 ms 10268 KB Output is correct
31 Correct 790 ms 10268 KB Output is correct
32 Correct 2849 ms 10268 KB Output is correct
33 Correct 1868 ms 10268 KB Output is correct
34 Correct 2621 ms 10268 KB Output is correct
35 Correct 2100 ms 10268 KB Output is correct
36 Correct 1839 ms 10268 KB Output is correct
37 Correct 4477 ms 10384 KB Output is correct
38 Correct 2593 ms 10384 KB Output is correct
39 Correct 3058 ms 10384 KB Output is correct
40 Correct 2575 ms 10384 KB Output is correct
41 Correct 5225 ms 10800 KB Output is correct
42 Correct 5554 ms 10800 KB Output is correct