Submission #290630

#	Time	Username	Problem	Language	Result	Execution time	Memory
290630		IgorI	Rectangles (IOI19_rect)	C++17	72 / 100	5152 ms	877480 KiB

rect

#include <bits/stdc++.h>

using namespace std;

const int INF = 88888888;
const int N = 2512;

typedef vector<vector<int> > vvi;
typedef vector<int> vi;

#define all(x) (x).begin(), (x).end()

int le[N][N], ri[N][N], up[N][N], down[N][N];

long long count_rectangles(vector<vector<int> > a)
{
    int n = a.size(), m = a[0].size();
    for (int i = 0; i < n; i++)
    {
        vector<pair<int, int> > st;
        st.push_back({-1, INF});
        for (int j = 0; j < m; j++)
        {
            while (st.back().second < a[i][j]) st.pop_back();
            le[i][j] = st.back().first;
            st.push_back({j, a[i][j]});
        }
    }
    for (int i = 0; i < n; i++)
    {
        vector<pair<int, int> > st;
        st.push_back({m, INF});
        for (int j = m - 1; j >= 0; j--)
        {
            while (st.back().second < a[i][j]) st.pop_back();
            ri[i][j] = st.back().first;
            st.push_back({j, a[i][j]});
        }
    }
    for (int j = 0; j < m; j++)
    {
        vector<pair<int, int> > st;
        st.push_back({-1, INF});
        for (int i = 0; i < n; i++)
        {
            while (st.back().second < a[i][j]) st.pop_back();
            up[i][j] = st.back().first;
            st.push_back({i, a[i][j]});
        }
    }
    for (int j = 0; j < m; j++)
    {
        vector<pair<int, int> > st;
        st.push_back({n, INF});
        for (int i = n - 1; i >= 0; i--)
        {
            while (st.back().second < a[i][j]) st.pop_back();
            down[i][j] = st.back().first;
            st.push_back({i, a[i][j]});
        }
    }
    vector<vector<vector<pair<int, int> > > > rooted(n, vector<vector<pair<int, int> > >(m));
    for (int i = 1; i + 1 < n; i++)
    {
        for (int j = 1; j + 1 < m; j++)
        {
            {
                int r = ri[i][j - 1] - 1;
                int u0 = up[i + 1][j] + 1;
                int u1 = up[i + 1][r] + 1;
                int d0 = down[i - 1][j] - 1;
                int d1 = down[i - 1][r] - 1;
                rooted[u0][j].push_back({i, r});
                rooted[u1][j].push_back({i, r});
                rooted[i][j].push_back({d0, r});
                rooted[i][j].push_back({d1, r});
            }
            {
                int l = le[i][j + 1] + 1;
                int u0 = up[i + 1][l] + 1;
                int u1 = up[i + 1][j] + 1;
                int d0 = down[i - 1][l] - 1;
                int d1 = down[i - 1][j] - 1;
                rooted[u0][l].push_back({i, j});
                rooted[u1][l].push_back({i, j});
                rooted[i][l].push_back({d0, j});
                rooted[i][l].push_back({d1, j});
            }
        }
    }
    int ans = 0;
    for (int i = 1; i < n; i++)
    {
        for (int j = 1; j < m; j++)
        {
            sort(all(rooted[i][j]));
            rooted[i][j].resize(unique(all(rooted[i][j])) - rooted[i][j].begin());
            for (auto p : rooted[i][j])
            {
                int i2 = p.first, j2 = p.second;
                if (i <= i2 && j <= j2 && i2 < n - 1 && j2 < m - 1)
                {
                    int t = 1;
                    for (int y = j; y <= j2; y++)
                        if (down[i - 1][y] <= i2) t = 0;
                    for (int y = j; y <= j2; y++)
                        if (up[i2 + 1][y] >= i) t = 0;
                    for (int x = i; x <= i2; x++)
                        if (ri[x][j - 1] <= j2) t = 0;
                    for (int x = i; x <= i2; x++)
                        if (le[x][j2 + 1] >= j) t = 0;
                    ans += t;
                }
            }
        }
    }
    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