1 #include<stdio.h>
 2  
 3 int dp[1005][1005],a[1005][1005];
 4  
 5 int main()
 6 {
 7     int n,m;
 8     for(int i=0;i<=1000;i++)
 9         dp[0][i]=dp[i][0]=0;
10     while(scanf("%d%d",&n,&m)>0)
11     {
12         for(int i=1;i<=n;i++)
13             for(int j=1;j<=m;j++)
14             scanf("%d",&a[i][j]);
15         int sum=0;
16         for(int i=1;i<=m;i++)
17         {
18             sum+=a[1][i]; dp[1][i]=sum;
19         }
20         for(int i=2;i<=n;i++)
21         {
22             sum=0;
23             for(int j=1;j<=m;j++)
24             {
25                sum+=a[i][j]; dp[i][j]=dp[i-1][j]+sum;
26             }
27         }
28         int maxk=0;
29         for(int i=n;i>0;i--)
30         for(int j=m;j>0&&maxk<i*j;j--)
31         if(a[i][j])
32         {
33             int r=1,c=1;
34             while(j-c>=0)
35             {
36                 if(dp[i][j]-dp[i][j-c]-dp[i-r][j]+dp[i-r][j-c]==r*c)
37                 {
38                      if(maxk<r*c) maxk=r*c; c++;
39                 }
40                 else
41                     break;
42             }
43             while(i-r>=0&&c>0)
44             {
45                 if(dp[i][j]-dp[i][j-c]-dp[i-r][j]+dp[i-r][j-c]==r*c)
46                 {
47                     if(maxk<r*c) maxk=r*c; r++;
48                 }
49                 else
50                     c--;
51             }
52         }
53         printf("%d\n",maxk);
54     }
55 }
56  
57 /**************************************************************
58     Problem: 1497
59     User: aking2015
60     Language: C++
61     Result: Accepted
62     Time:410 ms
63     Memory:8912 kb
64 ****************************************************************/

  1 #include <stdio.h>
  2 #include <string.h>
  3 #include <algorithm>
  4 using namespace std;
  5  
  6 int map[1005][1005];
  7 int col[1005][1005];
  8 int n,m,maxn;
  9  
 10 void set_col(int p)
 11 {
 12     int i,j,sum;
 13     for(i = 1; i<=n; i++)
 14     {
 15         if(!map[i][p])
 16             continue;
 17         j = i;
 18         sum = 0;
 19         while(map[j][p] && j<=n)
 20         {
 21             sum+=map[j][p];
 22             j++;
 23         }
 24         for(int k = i; k<j; k++)
 25             col[k][p] = sum;
 26         i = j;
 27     }
 28 }
 29  
 30 int find(int r,int c)
 31 {
 32     int i,j,val=map[r][c];
 33     int cnt = 1;
 34     for(i = r-1; i>0; i--)
 35     {
 36         if(val>map[i][c])
 37             break;
 38         cnt++;
 39     }
 40     for(i = r+1; i<=n; i++)
 41     {
 42         if(val>map[i][c])
 43             break;
 44         cnt++;
 45     }
 46     return val*cnt;
 47 }
 48  
 49 int solve()
 50 {
 51     int i,j;
 52     maxn = 0;
 53     for(i = 1; i<=n; i++)
 54     {
 55         for(j = 1; j<=m; j++)
 56         {
 57             if(maxn<col[i][j] && map[i][j])
 58             {
 59                 int val = find(i,j);
 60                 maxn = max(maxn,val);
 61             }
 62         }
 63     }
 64     return maxn;
 65 }
 66  
 67 int main()
 68 {
 69     int i,j;
 70     while(~scanf("%d%d",&n,&m))
 71     {
 72         for(i = 1; i<=n; i++)
 73         {
 74             for(j = 1; j<=m; j++)
 75                 scanf("%d",&map[i][j]);
 76         }
 77         for(i = 1; i<=n; i++)
 78         {
 79             for(j = 2; j<=m; j++)
 80             {
 81                 if(map[i][j]==1 && map[i][j-1])
 82                     map[i][j]=map[i][j-1]+1;
 83             }
 84         }
 85         for(i = 1; i<=m; i++)
 86             set_col(i);
 87         printf("%d\n",solve());
 88     }
 89  
 90     return 0;
 91 }
 92  
 93 /**************************************************************
 94     Problem: 1497
 95     User: aking2015
 96     Language: C++
 97     Result: Accepted
 98     Time:440 ms
 99     Memory:8912 kb
100 ****************************************************************/

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 using namespace std;
 5  
 6 int num[1005][1005];
 7 
 8 int len[1005][1005];
 9 int main()
10 {
11     int m,n;
12     int i,j;
13 
14     while(scanf("%d%d",&m,&n)!=EOF)
15     {
16         for(i=1; i<=m; i++)
17         {
18 
19             len[i][0]=0;
20             for(j=1; j<=n; j++)
21             {
22                 scanf("%d",&num[i][j]);
23 
24                 len[i][j]=len[i][j-1]+num[i][j];
25             }
26         }
27 
28         int mmax=0,x;
29         for(i=m; i>0; i--)
30         {
31             for(j=n; j>0; j--)
32             {
33  
34                 if(num[i][j]&&i*j>mmax)
35                 {
36                     int h=0,w=0;
37 
38                     int k;
39                     int ww=100000;
40                     for(x=i; x>0; x--)
41                     {
42                         if(!num[x][j]) break;
43                         h++;
44                         w=0;
45  
46                         for(k=j; k>0; k--)
47                         {
48                             if(len[x][k]==j)
49                             {
50                                 w=j;
51                                 break;
52                             }
53                             else if(num[x][k]&&len[x][j]-len[x][k]+1==j-k+1&&w<=ww)
54                             {
55                                 w++;
56                             }
57                             else break;
58                         }
59  
60                         ww=min(w,ww);
61                         mmax=max(mmax,ww*h);
62 
63                     }
64  
65  
66                 }
67  
68             }
69         }
70         printf("%d\n",mmax);
71     }
72     return 0;
73 }
74 /**************************************************************
75     Problem: 1497
76     User: aking2015
77     Language: C++
78     Result: Accepted
79     Time:440 ms
80     Memory:9408 kb
81 ****************************************************************/