我也过了，而且没开氧气优化
by szbszb @ 2019-11-08 19:09:50
带了点环境优化，最慢的点697ms：
```cpp
#include<bits/stdc++.h>
#pragma GCC diagnostic error "-std=c++14"
#pragma GCC target("avx")
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
using namespace std;
long long n,m,i,j,x,y,a[201][201],d[201][201],ans;
int main()
{
scanf("%lld%lld",&n,&m);
for (i=1;i<=n;i++)
for (j=1;j<=m;j++)
{
scanf("%lld",&a[i][j]);
d[i][j]=d[i][j-1]+d[i-1][j]-d[i-1][j-1]+a[i][j];
}
for (i=1;i<=n;i++)
for (j=1;j<=m;j++)
for (x=0;x<i;x++)
for (y=0;y<j;y++)
if (d[i][j]-d[x][j]-d[i][y]+d[x][y]>0)
ans=max(ans,(i-x)*(j-y));
printf("%lld",ans);
return 0;
}
```
by szbszb @ 2019-11-08 19:14:09