Submission #726475

#	Time	Username	Problem	Language	Result	Execution time	Memory
726475		LittleCube	Rectangles (IOI19_rect)	C++14	72 / 100	5074 ms	499168 KiB

rect

#ifndef EVAL
#include "grader.cpp"
#endif
#include "rect.h"
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;

struct BIT
{
	int bit[2505], N;
	void init(int n)
	{
		N = n;
		for (int i = 1; i <= N; i++)
			bit[i] = 0;
	}
	void modify(int pos, int val)
	{
		for (int i = pos + 1; i <= N; i += (i & -i))
			bit[i] += val;
	}
	int query(int pos)
	{
		int ans = 0;
		for (int i = pos + 1; i; i -= (i & -i))
			ans += bit[i];
		return ans;
	}

} bit[2500];

int N, M;
pii table[2500][2500];
vector<pii> ver[2500], hor[2500];
vector<tuple<int, int, int, int>> event[2500];
ll ans;

void add_query(int l, int r, pii range)
{
	if (range == pii(-1, -1))
		return;
	//fprintf(stderr, "query i = %d time %d range (%d, %d)\n", l, r, range.F, range.S);
	for (int i = range.F - 1; i <= range.S + 1; i++)
		event[l].emplace_back(make_tuple(r, 0, i, range.S + 1));
}

void add_modify(pii range, int u, int d)
{
	if (range == pii(-1, -1))
		return;
	//fprintf(stderr, "modify time range (%d, %d), up %d down %d\n", range.F, range.S, u, d);
	for (int i = range.F - 1; i <= range.S + 1; i++)
		event[i].emplace_back(make_tuple(range.S + 1, 1, u, d));
}

ll count_rectangles(vector<vector<int>> a)
{
	N = a.size(), M = a[0].size();

	if (N <= 2 || M <= 2)
		return 0;

	for (int i = 1; i + 1 < N; i++)
	{
		set<int> st;
		vector<int> o;
		for (int j = 0; j < M; j++)
			o.emplace_back(j);
		sort(o.begin(), o.end(), [&](int j, int k)
			 { return pii(a[i][j], -j) > pii(a[i][k], -k); });
		for (int j = 0; j < M; j++)
		{
			auto iter = st.insert(o[j]).F;
			if (iter != st.begin())
				if (*prev(iter) + 2 <= *iter)
					ver[i].emplace_back(pii(*prev(iter), *iter));
			if (next(iter) != st.end() && !(j + 1 < M && a[i][o[j]] == a[i][o[j + 1]] && o[j + 1] < *next(iter)))
				if (*iter + 2 <= *next(iter))
					ver[i].emplace_back(pii(*iter, *next(iter)));
		}
	}

	// for (int i = 1; i + 1 < N; i++)
	// 	for (auto [x, y] : ver[i])
	// 		cout << i << ' ' << x << ' ' << y << '\n';

	for (int i = 0; i < M; i++)
		for (int j = 0; j < M; j++)
			table[i][j] = pii(-1, -1);

	for (int i = 1; i + 1 < N; i++)
		for (auto [x, y] : ver[i])
			if (table[x][y].S == i - 1)
				table[x][y].S++;
			else
			{
				add_query(x, y, table[x][y]);
				table[x][y] = pii(i, i);
			}

	for (int i = 0; i < M; i++)
		for (int j = 0; j < M; j++)
			add_query(i, j, table[i][j]);

	for (int i = 1; i + 1 < M; i++)
	{
		set<int> st;
		vector<int> o;
		for (int j = 0; j < N; j++)
			o.emplace_back(j);
		sort(o.begin(), o.end(), [&](int j, int k)
			 { return pii(a[j][i], -j) > pii(a[k][i], -k); });
		for (int j = 0; j < N; j++)
		{
			auto iter = st.insert(o[j]).F;
			if (iter != st.begin())
				if (*prev(iter) + 2 <= *iter)
					hor[i].emplace_back(pii(*prev(iter), *iter));
			if (next(iter) != st.end() && !(j + 1 < N && a[o[j]][i] == a[o[j + 1]][i] && o[j + 1] < *next(iter)))
				if (*iter + 2 <= *next(iter))
					hor[i].emplace_back(pii(*iter, *next(iter)));
		}
	}

	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			table[i][j] = pii(-1, -1);

	for (int i = 1; i + 1 < M; i++)
		for (auto [x, y] : hor[i])
			if (table[x][y].S == i - 1)
				table[x][y].S++;
			else
			{
				add_modify(table[x][y], x, y);
				table[x][y] = pii(i, i);
			}

	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			add_modify(table[i][j], i, j);

	for (int i = 0; i < N; i++)
		bit[i].init(N);
	for (int i = 0; i < M; i++)
	{
		sort(event[i].begin(), event[i].end(), greater<>());
		for (auto [_, t, l, r] : event[i])
		{
			if (t == 1)
				bit[l].modify(r, 1);
			else
				ans += bit[l].query(r);
		}
		for (auto [_, t, l, r] : event[i])
			if (t == 1)
				bit[l].modify(r, -1);
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:97:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   97 |   for (auto [x, y] : ver[i])
      |             ^
rect.cpp:135:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  135 |   for (auto [x, y] : hor[i])
      |             ^
rect.cpp:153:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  153 |   for (auto [_, t, l, r] : event[i])
      |             ^
rect.cpp:160:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  160 |   for (auto [_, t, l, r] : event[i])
      |             ^

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 22 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28