From Evernote:

uva 836

最大子矩陣
tmp如果沒有跟紀錄上的lon跟wid一樣就設為0，代表子矩陣內有0，如果一模一樣就記錄起來，並且MAX化

[sourcecode language="cpp"]

//============================================================================
// Name : Largest Submatrix.cpp
// Date : 2013 2013/2/1 下午9:55:17
// Author : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
typedef long long ll;
typedef unsigned int uint;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
printf("%d ",dp[htx][hty]);}Pln();}
#define M 105
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define Is_debug true
#define debug(...) if(Is_debug)printf("DEBUG: "),printf(__VA_ARGS__)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
int dp[M][M],sum[M];
char mz[M][M];
char cl[3];
int main() {
ios_base::sync_with_stdio(0);
int n;
scanf("%d%*c",&n);
while(n--){
Set(sum,0);
int bx,by;
gets(cl);
gets(mz[0]);
bx=by=strlen(mz[0]);
for(int i=1;i<by;i++){
gets(mz[i]);
}
Set(dp,0);
int ans=0;
for(int i=0;i<by;i++){
Set(sum,0);
for(int j=i;j<by;j++){
int lon=0,wid,tmp=0;
for(int k=0;k<bx;k++){
sum[k]+=mz[j][k]-'0';
if(tmp!=lon*wid){
tmp=0;
lon=0;
}
tmp+=sum[k];
lon++;wid=j-i+1;
if(tmp==lon*wid){
ans=max(ans,tmp);
}
}
}
}
printf("%d\n",ans);
if(n)Pln();
}

}

[/sourcecode]