#include "soccer.h"
#include <bits/stdc++.h>
using namespace std;
const int MAX = 2005;
const int LOG = 15;
int n, a[MAX][MAX];
int L[MAX][MAX];
int R[MAX][MAX];
int U[MAX][MAX];
int D[MAX][MAX];
int go[MAX][MAX];
int logs[MAX];
int st_U[MAX][MAX][LOG];
int st_D[MAX][MAX][LOG];
int res;
map<array<int, 4>, int> mx;
int query_U(int i, int l, int r) {
int k = logs[r - l + 1];
return max(st_U[i][l][k], st_U[i][r - (1 << k) + 1][k]);
}
int query_D(int i, int l, int r) {
int k = logs[r - l + 1];
return min(st_D[i][l][k], st_D[i][r - (1 << k) + 1][k]);
}
void rec(int xl, int xr, int yl, int yr, int side, int cur) {
if (mx[{xl, xr, yl, yr}] >= cur) {
return;
}
res = max(res, cur);
mx[{xl, xr, yl, yr}] = cur;
vector<array<int, 5>> f;
if (xl > 0) {
// up
int ptr = yl;
while (ptr <= yr) {
if (a[xl - 1][ptr] == 1) {
ptr = go[xl - 1][ptr];
continue;
}
int t = min(yr, R[xl - 1][ptr]);
int new_x = query_U(xl - 1, ptr, t);
//f.push_back({(t - ptr + 1) * (xl - new_x), new_x, xr, ptr, t});
rec(new_x, xr, ptr, t, 1, cur + (t - ptr + 1) * (xl - new_x));
ptr = R[xl - 1][ptr] + 1;
}
}
if (xr + 1 < n) {
// down
int ptr = yl;
while (ptr <= yr) {
if (a[xr + 1][ptr] == 1) {
ptr = go[xr + 1][ptr];
continue;
}
int t = min(yr, R[xr + 1][ptr]);
int new_x = query_D(xr + 1, ptr, t);
f.push_back({(t - ptr + 1) * (new_x - xr), xl, new_x, ptr, t});
//rec(xl, xr + 1, ptr, t, 0, cur + t - ptr + 1);
ptr = R[xr + 1][ptr] + 1;
}
}
sort(f.rbegin(), f.rend());
for (auto& p : f) {
int sd = (p[1] == xl ? 0 : 1);
rec(p[1], p[2], p[3], p[4], sd, cur + p[0]);
}
}
int biggest_stadium(int N, vector<vector<int>> F) {
n = N;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
a[i][j] = F[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (a[i][j] == 1) {
continue;
}
int p = j;
while (p + 1 < n && a[i][p + 1] == 0) {
p += 1;
}
for (int k = j; k <= p; k++) {
L[i][k] = j;
R[i][k] = p;
}
j = p;
}
}
for (int j = 0; j < n; j++) {
for (int i = 0; i < n; i++) {
if (a[i][j] == 1) {
continue;
}
int p = i;
while (p + 1 < n && a[p + 1][j] == 0) {
p += 1;
}
for (int k = i; k <= p; k++) {
U[k][j] = i;
D[k][j] = p;
}
i = p;
}
}
for (int i = 2; i <= n; i++) {
logs[i] = logs[i >> 1] + 1;
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
st_U[i][j][0] = U[i][j];
st_D[i][j][0] = D[i][j];
}
}
for (int k = 1; k < LOG; k++) {
for (int i = 0; i < n; i++) {
for (int j = 0; j + (1 << k) <= n; j++) {
st_U[i][j][k] = max(st_U[i][j][k - 1], st_U[i][j + (1 << (k - 1))][k - 1]);
st_D[i][j][k] = min(st_D[i][j][k - 1], st_D[i][j + (1 << (k - 1))][k - 1]);
}
}
}
for (int i = 0; i < n; i++) {
for (int j = n - 1; j >= 0; j--) {
if (a[i][j] == 1) {
go[i][j] = (j == n - 1 ? n : go[i][j + 1]);
} else {
go[i][j] = j;
}
}
}
res = 0;
vector<array<int, 4>> s;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (a[i][j] == 1) {
continue;
}
if (j == 0 || a[i][j - 1] == 1) {
s.push_back({R[i][j] - j + 1, i, j, R[i][j]});
}
}
}
sort(s.rbegin(), s.rend());
for (auto& p : s) {
int i = p[1];
int l = p[2], r = p[3];
rec(i, i, l, r, -1, r - l + 1);
}
return res;
}
