编程题：求一个矩阵中最大的二维子矩阵（即二维子矩阵的和最大）好未来

 1 #!/usr/bin/env python
 2 
 3 def find_the_max(ary):
 4     max_val = 0
 5     for i in range(len(ary)-1):
 6         for j in range(len(ary[i])-1):
 7             sum_val = ary[i][j] + ary[i+1][j] + ary[i][j+1] + ary[i+1][j+1]
 8             if sum_val > max_val:
 9                 max_val = sum_val
10     return max_val
11 
12 def find_the_max1(ary):
13     max_val = 0
14     lastsum_val = ary[0][0] + ary[1][0]
15     for i in range(len(ary)-1):
16         for j in range(1,len(ary[i])):
17             sum_val = lastsum_val
18             lastsum_val = ary[i][j] + ary[i+1][j]
19             sum_val += lastsum_val
20             if sum_val > max_val:
21                 max_val = sum_val
22     return max_val
23 
24 if __name__=="__main__":
25     ary = [[1,2,0,3,4],[2,3,4,5,1],[1,10,5,3,0]]
26     print(find_the_max(ary))
27     print(find_the_max1(ary))