Submission #219792

#	Time	Username	Problem	Language	Result	Execution time	Memory
219792		VEGAnn	Rectangles (IOI19_rect)	C++14	50 / 100	5088 ms	318204 KiB

rect

#include <bits/stdc++.h>
#include "rect.h"
#define all(x) x.begin(),x.end()
#define PB push_back
#define sz(x) ((int)x.size())
using namespace std;
typedef long long ll;
const int N = 2600;
const int oo = 2e9;
bool mrk[N][N];
int n, m, kol = 0, mx, my, Mx, My;
ll ans = 0, big = 0;

void dfs(int x, int y){
    if (mrk[x][y]) return;
    kol++;
    mrk[x][y] = 1;
    mx = min(mx, x);
    my = min(my, y);
    Mx = max(Mx, x);
    My = max(My, y);

    if (x > 0) dfs(x - 1, y);
    if (y > 0) dfs(x, y - 1);
    if (y < m - 1) dfs(x, y + 1);
    if (x < n - 1) dfs(x + 1, y);
}

long long count_rectangles(std::vector<std::vector<int> > a) {
    n = sz(a);
    m = sz(a[0]);

    for (int x = 1; x <= n; x++)
        for (int y = 1; y <= m; y++)
            big += (n / x) * (m / y);

    if (n < 3 || m < 3) return 0;

    bool ok = 1;

    for (int i = 0; i < n && ok; i++)
        for (int j = 0; j < m && ok; j++) {
            ok &= bool(a[i][j] < 2);
            mrk[i][j] = a[i][j];
        }

    if (ok){
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                if (!mrk[i][j]){
                    mx = my = oo;
                    Mx = My = -oo;
                    kol = 0;

                    dfs(i, j);

                    if ((Mx - mx + 1) * (My - my + 1) == kol && mx > 0 && my > 0 && Mx < n - 1 && My < m - 1)
                        ans++;
                }
        return ans;
    }

    for (int r1 = 1; r1 < n - 1; r1++)
    for (int r2 = r1; r2 < n - 1; r2++)
    for (int c1 = 1; c1 < m - 1; c1++)
    for (int c2 = c1; c2 < m - 1; c2++){
        bool ok = 1;

        for (int i = r1; i <= r2 && ok; i++)
        for (int j = c1; j <= c2 && ok; j++){
            ok &= bool(a[i][j] < a[i][c1 - 1]);
            ok &= bool(a[i][j] < a[i][c2 + 1]);
            ok &= bool(a[i][j] < a[r2 + 1][j]);
            ok &= bool(a[i][j] < a[r1 - 1][j]);
        }

        ans += ok;
    }

    assert(ans <= big / 5);

	return ans;
}

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