oj.uz

Submission #59085

# Submission time Handle Problem Language Result Execution time Memory
59085 2018-07-20T13:31:20 Z fallingstar Dancing Elephants (IOI11_elephants) C++14
97 / 100
 9000 ms 34416 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;
	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 = 387;

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;
	}
}

void Rebuild()
{
	vector<pair<int, int> > arr;
	for (const auto &seg: a)
		for (const auto &e: seg)
			arr.push_back({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 = 387;
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 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 2 ms 432 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 2 ms 432 KB Output is correct
4 Correct 3 ms 508 KB Output is correct
5 Correct 3 ms 508 KB Output is correct
6 Correct 3 ms 508 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 2 ms 432 KB Output is correct
4 Correct 3 ms 508 KB Output is correct
5 Correct 3 ms 508 KB Output is correct
6 Correct 3 ms 508 KB Output is correct
7 Correct 405 ms 2244 KB Output is correct
8 Correct 504 ms 2480 KB Output is correct
9 Correct 1020 ms 5076 KB Output is correct
10 Correct 1558 ms 5076 KB Output is correct
11 Correct 1588 ms 5088 KB Output is correct
12 Correct 1378 ms 5144 KB Output is correct
13 Correct 2264 ms 5144 KB Output is correct

Subtask #4
47.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 2 ms 432 KB Output is correct
4 Correct 3 ms 508 KB Output is correct
5 Correct 3 ms 508 KB Output is correct
6 Correct 3 ms 508 KB Output is correct
7 Correct 405 ms 2244 KB Output is correct
8 Correct 504 ms 2480 KB Output is correct
9 Correct 1020 ms 5076 KB Output is correct
10 Correct 1558 ms 5076 KB Output is correct
11 Correct 1588 ms 5088 KB Output is correct
12 Correct 1378 ms 5144 KB Output is correct
13 Correct 2264 ms 5144 KB Output is correct
14 Correct 927 ms 5144 KB Output is correct
15 Correct 676 ms 5144 KB Output is correct
16 Correct 3004 ms 8600 KB Output is correct
17 Correct 2952 ms 12452 KB Output is correct
18 Correct 3424 ms 14412 KB Output is correct
19 Correct 1570 ms 16608 KB Output is correct
20 Correct 2914 ms 18728 KB Output is correct
21 Correct 2837 ms 20748 KB Output is correct
22 Correct 4742 ms 22372 KB Output is correct

Subtask #5
0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 2 ms 432 KB Output is correct
4 Correct 3 ms 508 KB Output is correct
5 Correct 3 ms 508 KB Output is correct
6 Correct 3 ms 508 KB Output is correct
7 Correct 405 ms 2244 KB Output is correct
8 Correct 504 ms 2480 KB Output is correct
9 Correct 1020 ms 5076 KB Output is correct
10 Correct 1558 ms 5076 KB Output is correct
11 Correct 1588 ms 5088 KB Output is correct
12 Correct 1378 ms 5144 KB Output is correct
13 Correct 2264 ms 5144 KB Output is correct
14 Correct 927 ms 5144 KB Output is correct
15 Correct 676 ms 5144 KB Output is correct
16 Correct 3004 ms 8600 KB Output is correct
17 Correct 2952 ms 12452 KB Output is correct
18 Correct 3424 ms 14412 KB Output is correct
19 Correct 1570 ms 16608 KB Output is correct
20 Correct 2914 ms 18728 KB Output is correct
21 Correct 2837 ms 20748 KB Output is correct
22 Correct 4742 ms 22372 KB Output is correct
23 Execution timed out 9099 ms 34416 KB Time limit exceeded
24 Halted 0 ms 0 KB -