/*
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("O3")
#pragma GCC target ("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
*/
#include<bits/stdc++.h>
#define ld long double
#define sz(v) (int)v.size()
#define ll long long
#define pb push_back
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define nl "\n"
using namespace std;
const int N = (int)25e2 + 7; // make sure this is right
const int M = (int)1e6 + 7;
const int B = 351;
const int inf = (int)2e9 + 7;
const ll INF = (ll)3e18 + 7;
const ll MOD = (ll)1e9 + 7; // make sure this is right
bool bit(int x, int i) {
return x >> i & 1;
}
int mult(int x, int y) {
return 1ll * x * y % MOD;
}
int sum(int x, int y) {
x += y;
if(x >= MOD) x -= MOD;
return x;
}
int n, m, p[N][N], e[N][N];
char a[N][N];
int get(int x1, int y1, int x2, int y2) {
return (p[x2][y2] - p[x1 - 1][y2] - p[x2][y1 - 1] + p[x1 - 1][y1 - 1]);
}
void solve() {
cin >> n >> m;
for(int i = 1; i <= n; ++i) {
for(int j = 1; j <= m; ++j) {
cin >> a[i][j];
p[i][j] = p[i - 1][j] + p[i][j - 1] - p[i - 1][j - 1] + (a[i][j] == '1');
}
}
int ans = 0;
for(int h = 1; h <= n; ++h) {
int l = 1, r = m;
while(l <= r) {
int w = (l + r) >> 1;
for(int i = 1; i <= n - h + 1; ++i) {
for(int j = 1; j <= m - w + 1; ++j) {
int ii = i + h - 1, jj = j + w - 1;
int x = get(i, j, ii, jj);
if(x == h * w) {
e[i][j]++;
e[i][jj + 1]--;
e[ii + 1][j]--;
e[ii + 1][jj + 1]++;
}
}
}
for(int i = 1; i <= n && ok; ++i) {
for(int j = 1; j <= m && ok; ++j) {
e[i][j] += e[i - 1][j];
e[i][j] += e[i][j - 1];
e[i][j] -= e[i - 1][j - 1];
if(a[i][j] == '1') {
ok &= (e[i][j] > 0);
}
}
}
for(int i = 1; i <= n; ++i) {
for(int j = 1; j <= m; ++j) {
e[i][j] = 0;
}
}
if(ok) {
ans = max(ans, h * w);
l = w + 1;
} else
r = w - 1;
}
}
cout << ans << "\n";
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int test = 1;
//cin >> test;
for(int i = 1; i <= test; ++i) {
//cout << "Case #" << i << ": ";
solve();
}
return 0;
}
Compilation message
bomb.cpp: In function 'void solve()':
bomb.cpp:77:29: error: 'ok' was not declared in this scope
77 | for(int i = 1; i <= n && ok; ++i) {
| ^~
bomb.cpp:92:7: error: 'ok' was not declared in this scope
92 | if(ok) {
| ^~
