def incidence_matrix_to_list(incimatrix):
"""
Convert from an incidence matrix to adjacency lists.
:param incimatrix: Input incidence matrix[nodeindex][edgeindex]
:param edgemap: dictionary{(edge):edgeindex}
:return: adjacent linked list
"""
nodenum = len(incimatrix)
edgenum = len(incimatrix[0])
# # switch map to index:tuple
# reversemap = {}
# for key, value in edgemap.items():
# reversemap[value] = key
lst = [SLL.LinkedList() for _ in range(nodenum)]
for edge_index in range(edgenum):
temppair = []
for node_index in range(nodenum):
if incimatrix[node_index][edge_index] == 1:
temppair.append(node_index)
lst[temppair[0]].append(temppair[1])
lst[temppair[1]].append(temppair[0])
# for node_index in range(nodenum):
# for edge_index in range(edgenum):
# if incimatrix[node_index][edge_index] == 1:
# edge = reversemap[edge_index]
# node = edge[0] if node_index != edge[0] else edge[1]
# lst[node_index].append(node)
return lst
def matrix_to_list(matrix):
"""
Convert from an adjacency matrix to adjacency lists
:param matrix: Input adjacency matrix[][]
:return: Output a list of linked list, each linked list store the neighbours
"""
length = len(matrix)
lst = [SLL.LinkedList() for _ in range(length)]
for i in range(length):
for j in range(length):
if matrix[i][j] == 1:
lst[i].append(j)
return lst