oj.uz

Submission #59090

# Submission time Handle Problem Language Result Execution time Memory
59090 2018-07-20T13:42:32 Z fallingstar Dancing Elephants (IOI11_elephants) C++14
97 / 100
 9000 ms 11812 KB 
#include "elephants.h"
#include <list>
#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
	}
}; 

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

const int BLOCK_SIZE = 600;

void Calc(list<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();
	list<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;
	list<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 = 1200;
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
	for (auto i = a.begin(); i != a.end(); ++i)
		if (!(i->back() < old_ele))					// i->back >= old_ele
		{
			list<TElephant> leftSeg;
			for (auto it = i->begin(); it != i->end(); ++it)
				if (it->id == idx)
				{
					// cut segment into 2 parts
					leftSeg.splice(leftSeg.end(), *i, i->begin(), next(it));
					break;
				}
			if (i->empty()) i = a.erase(i);
			leftSeg.pop_back();
			if (!leftSeg.empty()) 
			{
				Calc(leftSeg);
				a.insert(i, move(leftSeg));
			}
			break;
		}
	
	// insert idx to new position
	if (a.empty()) 
		a.push_back(list<TElephant>(1, new_ele)); 
	else if (a.back().back() < new_ele)
	{
		a.back().push_back(new_ele);
		Calc(a.back());
	}	
	else 
		for (auto i = a.begin(); i != a.end(); ++i)
			if (new_ele < i->back())
			{
				for (auto it = i->begin(); it != i->end(); ++it)
					if (new_ele < *it)
					{
						i->insert(it, new_ele);
						break;
					}
				Calc(*i);
				break;
			}
	
	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 3 ms 488 KB Output is correct
3 Correct 2 ms 544 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 3 ms 488 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 3 ms 544 KB Output is correct
5 Correct 4 ms 548 KB Output is correct
6 Correct 3 ms 724 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 3 ms 488 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 3 ms 544 KB Output is correct
5 Correct 4 ms 548 KB Output is correct
6 Correct 3 ms 724 KB Output is correct
7 Correct 558 ms 2004 KB Output is correct
8 Correct 651 ms 2316 KB Output is correct
9 Correct 824 ms 4456 KB Output is correct
10 Correct 810 ms 4456 KB Output is correct
11 Correct 1877 ms 4476 KB Output is correct
12 Correct 1514 ms 4576 KB Output is correct
13 Correct 1499 ms 4576 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 3 ms 488 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 3 ms 544 KB Output is correct
5 Correct 4 ms 548 KB Output is correct
6 Correct 3 ms 724 KB Output is correct
7 Correct 558 ms 2004 KB Output is correct
8 Correct 651 ms 2316 KB Output is correct
9 Correct 824 ms 4456 KB Output is correct
10 Correct 810 ms 4456 KB Output is correct
11 Correct 1877 ms 4476 KB Output is correct
12 Correct 1514 ms 4576 KB Output is correct
13 Correct 1499 ms 4576 KB Output is correct
14 Correct 1430 ms 4576 KB Output is correct
15 Correct 1032 ms 4576 KB Output is correct
16 Correct 2219 ms 4752 KB Output is correct
17 Correct 2565 ms 5932 KB Output is correct
18 Correct 2856 ms 6028 KB Output is correct
19 Correct 1087 ms 6028 KB Output is correct
20 Correct 2512 ms 6028 KB Output is correct
21 Correct 2643 ms 6040 KB Output is correct
22 Correct 2536 ms 6040 KB Output is correct

Subtask #5
0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 488 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 3 ms 544 KB Output is correct
5 Correct 4 ms 548 KB Output is correct
6 Correct 3 ms 724 KB Output is correct
7 Correct 558 ms 2004 KB Output is correct
8 Correct 651 ms 2316 KB Output is correct
9 Correct 824 ms 4456 KB Output is correct
10 Correct 810 ms 4456 KB Output is correct
11 Correct 1877 ms 4476 KB Output is correct
12 Correct 1514 ms 4576 KB Output is correct
13 Correct 1499 ms 4576 KB Output is correct
14 Correct 1430 ms 4576 KB Output is correct
15 Correct 1032 ms 4576 KB Output is correct
16 Correct 2219 ms 4752 KB Output is correct
17 Correct 2565 ms 5932 KB Output is correct
18 Correct 2856 ms 6028 KB Output is correct
19 Correct 1087 ms 6028 KB Output is correct
20 Correct 2512 ms 6028 KB Output is correct
21 Correct 2643 ms 6040 KB Output is correct
22 Correct 2536 ms 6040 KB Output is correct
23 Execution timed out 9065 ms 11812 KB Time limit exceeded
24 Halted 0 ms 0 KB -