Submission #295399

#	Time	Username	Problem	Language	Result	Execution time	Memory
295399		SamAnd	Rectangles (IOI19_rect)	C++17	72 / 100	5050 ms	255048 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
typedef long long ll;
const int N = 2505;
const int xx[4] = {1, 0, -1, 0};
const int yy[4] = {0, 1, 0, -1};

int n, m;
int a[N][N];

bool c[N][N];
int q;
int minx, maxx, miny, maxy;

void dfs(int x, int y)
{
    c[x][y] = true;
    ++q;
    minx = min(minx, x);
    maxx = max(maxx, x);
    miny = min(miny, y);
    maxy = max(maxy, y);
    for (int i = 0; i < 4; ++i)
    {
        int hx = x + xx[i];
        int hy = y + yy[i];
        if (hx >= 1 && hx <= n && hy >= 1 && hy <= m && !c[hx][hy] && a[hx][hy] == 0)
        {
            dfs(hx, hy);
        }
    }
}

ll solv6()
{
    ll ans = 0;
    for (int x = 1; x <= n; ++x)
    {
        for (int y = 1; y <= m; ++y)
        {
            if (a[x][y] == 0)
            {
                if (!c[x][y])
                {
                    q = 0;
                    minx = maxx = x;
                    miny = maxy = y;
                    dfs(x, y);
                    if (minx == 1 || maxx == n)
                        continue;
                    if (miny == 1 || maxy == m)
                        continue;
                    if ((maxx - minx + 1) * (maxy - miny + 1) == q)
                    {
                        ++ans;
                    }
                }
            }
        }
    }
    return ans;
}

int l[N][N], r[N][N];

int maxu[N];
int ul[N], ur[N];

long long count_rectangles(std::vector<std::vector<int> > A)
{
    n = sz(A);
    m = sz(A[0]);
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            a[i][j] = A[i - 1][j - 1];
        }
    }

    bool z = true;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            if (a[i][j] > 1)
            {
                z = false;
            }
        }
    }

    if (z)
    {
        return solv6();
    }

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            l[i][j] = j;
            while (l[i][j] > 1 && a[i][j] > a[i][l[i][j] - 1])
                --l[i][j];
            r[i][j] = j;
            while (r[i][j] < m && a[i][j] > a[i][r[i][j] + 1])
                ++r[i][j];
        }
    }

    ll ans = 0;
    for (int x1 = 2; x1 < n; ++x1)
    {
        for (int x2 = x1; x2 < n; ++x2)
        {
            for (int y = 1; y <= m; ++y)
            {
                if (x2 == x1)
                {
                    maxu[y] = a[x2][y];
                    ul[y] = l[x2][y];
                    ur[y] = r[x2][y];
                }
                else
                {
                    maxu[y] = max(maxu[y], a[x2][y]);
                    ul[y] = max(ul[y], l[x2][y]);
                    ur[y] = min(ur[y], r[x2][y]);
                }
            }
            for (int y1_ = 2; y1_ < m; ++y1_)
            {
                for (int y2 = y1_; y2 < m; ++y2)
                {
                    if (maxu[y2] >= a[x1 - 1][y2])
                        break;
                    if (maxu[y2] >= a[x2 + 1][y2])
                        break;
                    if (ur[y1_ - 1] >= y2 && ul[y2 + 1] <= y1_)
                        ++ans;
                }
            }
        }
    }
	return ans;
}

• 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