1 #include "stdio.h"
 2 #include "string.h"
 3 #include "math.h"
 4 #include "stdlib.h"
 5
 6 #define Reset(a) memset(a, 0, sizeof(a))
 7 #define MAX 1000000000
 8
 9 int dir[4][2]={{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
10
11 struct high
12 {
13     int x, y;
14     int h;
15 };
16
17 int cmp(const void *_a, const void *_b)
18 {
19     struct high a=*(struct high *)_a;
20     struct high b=*(struct high *)_b;
21
22     return a.h-b.h;
23 }
24
25 int main()
26 {
27     int n, m;
28     while (~scanf("%d%d", &n, &m))
29     {
30         int h[n+2][m+2], dp[n+2][m+2];
31         struct high rec[n*m];
32
33         memset(h, 255, sizeof(h));
34         for (int i=1; i<=n; i++)
35             for (int j=1; j<=m; j++)
36             {
37                 scanf("%d", &h[i][j]);
38                 rec[(i-1)*m+j-1].h=h[i][j];
39                 rec[(i-1)*m+j-1].x=i;
40                 rec[(i-1)*m+j-1].y=j;
41             }
42         Reset(dp);
43         qsort(rec, n*m, sizeof(struct high), cmp);
44         int ans=0;
45         for (int i=0, tmp=n*m; i<tmp; i++)
46         {
47             int max=0;
48
49             for (int j=0; j<4; j++)
50             {
51                 if (max < dp[rec[i].x-dir[j][0]][rec[i].y-dir[j][1]]+1
52                     && h[rec[i].x-dir[j][0]][rec[i].y-dir[j][1]]!=h[rec[i].x][rec[i].y])
53                     max = dp[rec[i].x-dir[j][0]][rec[i].y-dir[j][1]]+1;
54                 dp[rec[i].x][rec[i].y] = max;
55             }
56             if(ans<max)
57                 ans=max;
58         }
59 /**
60         for (int i=1; i<=n; i++)
61         {
62             for (int j=1; j<=m; j++)
63                 printf("%4d ", dp[i][j]);
64             puts("");
65         }
66 /**/
67         printf("%d\n", ans);
68     }
69
70     return 0;
71 }