Submission #290621

#	Time	Username	Problem	Language	Result	Execution time	Memory
290621		IgorI	Rectangles (IOI19_rect)	C++17	59 / 100	4932 ms	1048580 KiB

rect

#include <bits/stdc++.h>

using namespace std;

const int INF = 88888888;

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

struct rect{
    int x1, y1, x2, y2;
    bool operator == (rect b){
        return b.x1 == x1 && b.y1 == y1 && b.x2 == x2 && b.y2 == y2;
    }
};

bool comp(rect a, rect b)
{
    return pair<pair<int, int>, pair<int, int> >{{a.x1, a.y1}, {a.x2, a.y2}} < 
           pair<pair<int, int>, pair<int, int> >{{b.x1, b.y1}, {b.x2, b.y2}};
}

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

long long count_rectangles(vector<vector<int> > a)
{
    int n = a.size(), m = a[0].size();
    vvi le(n, vi(m)), ri(n, vi(m)), up(n, vi(m)), down(n, vi(m));
    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<rect> ch;
    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;
                ch.push_back({u0, j, i, r});
                ch.push_back({u1, j, i, r});
                ch.push_back({i, j, d0, r});
                ch.push_back({i, j, 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;
                ch.push_back({u0, l, i, j});
                ch.push_back({u1, l, i, j});
                ch.push_back({i, l, d0, j});
                ch.push_back({i, l, d1, j});
            }
        }
    }
    sort(all(ch), comp);
    int ans = 0;
    for (int i = 0; i < ch.size(); i++)
    {
        if (i && ch[i] == ch[i - 1]) continue;
        if (ch[i].x1 <= ch[i].x2 && ch[i].y1 <= ch[i].y2 && 1 <= ch[i].x1 && 1 <= ch[i].y1 && ch[i].x2 < n - 1 && ch[i].y2 < m - 1)
        {
            int t = 1;
            for (int j = ch[i].y1; j <= ch[i].y2; j++) if (down[ch[i].x1 - 1][j] <= ch[i].x2) t = 0;
            for (int j = ch[i].y1; j <= ch[i].y2; j++) if (up[ch[i].x2 + 1][j] >= ch[i].x1) t = 0;
            for (int j = ch[i].x1; j <= ch[i].x2; j++) if (ri[j][ch[i].y1 - 1] <= ch[i].y2) t = 0;
            for (int j = ch[i].x1; j <= ch[i].x2; j++) if (le[j][ch[i].y2 + 1] >= ch[i].y1) t = 0;
            if (t)
            {
                ans++;
                //cout << ch[i].x1 << " " << ch[i].y1 << " " << ch[i].x2 << " " << ch[i].y2 << "\n";
            }
        }
    }
    return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:104:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<rect>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |     for (int i = 0; i < ch.size(); i++)
      |                     ~~^~~~~~~~~~~

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