我需要找到给定矩阵mxn的所有可能的子矩阵.我试图在python中这样做,不想使用numpy.我们可以只使用循环吗？
例如：2×2矩阵
Matrix = [
[1,2],[3,4]
]
Submatrices =[ [1],[1,[2],[3],[4],4],[[1],[3]],[[2],[4]],[[1,4]] ]
最佳答案
假设矩阵
Matrix = [
[1,2,3],4,5],[5,6,7]
]
分为3个功能：
def ContinSubSeq(lst):
size=len(lst)
for start in range(size):
for end in range(start+1,size+1):
yield (start,end)
def getsubmat(mat,start_row,end_row,start_col,end_col):
return [i[start_col:end_col] for i in mat[start_row:end_row] ]
def get_all_sub_mat(mat):
rows = len(mat)
cols = len(mat[0])
for start_row,end_row in ContinSubSeq(list(range(rows))):
for start_col,end_col in ContinSubSeq(list(range(cols))):
yield getsubmat(mat,end_col)
运行这个
for i in get_all_sub_mat(Matrix):
print i
或者更简单,放入一个功能：
def get_all_sub_mat(mat):
rows = len(mat)
cols = len(mat[0])
def ContinSubSeq(lst):
size=len(lst)
for start in range(size):
for end in range(start+1,size+1):
yield (start,end)
for start_row,end_row in ContinSubSeq(list(range(rows))):
for start_col,end_col in ContinSubSeq(list(range(cols))):
yield [i[start_col:end_col] for i in mat[start_row:end_row] ]