def add_edge(self, vi, vj, val=1):
if self._vnum == 0:
raise GraphError("Cannot add edge to empty graph.")
if self._invalid(vi) or self._invalid(vj):
raise GraphError("{} or {} is not a valid vertex".format(vi, vj))
row = self._mat[vi]
i = 0
while i < len(row):
if row[i][0] == vj: # 如果原图存在 vi 到 vj 的边，则用新的 vi 到 vj 的权值覆盖掉原有的权值
self._mat[vi][i] = (vj, val) # 修改 mat[vi][vj] 的权值
return
if row[i][0] > vj: # 如果原图中没有到vj的边，跳出循环后加入此边
break
i += 1
self._mat[vi].insert(i, (vj, val))
def get_edge(self, vi, vj):
if self._invalid(vi) or self._invalid(vj):
raise GraphError("{} or {} is not a valid vertex".format(vi, vj))
for i, val in self._mat[vi]:
if i == vj:
return val
return self._unconn
def __init__(self, mat=None, unconn=0):
if mat is None:
mat = []
vnum = len(mat)
for x in mat:
if len(x) != vnum: # 行数与列数做对比，检查邻接矩阵是否为合法的方阵
raise GraphError("Argument for 'Graph'.")
self._mat = [self._out_edges(mat[i], unconn) for i in range(vnum)]
self._vnum = vnum
self._unconn = unconn
def __init__(self, mat, unconn=0):
"""
构造方法
:param mat: 邻接矩阵，嵌套列表
:param unconn: 无关联情况的特殊值，默认为0
"""
vnum = len(mat) # 获取邻接矩阵行数
for x in mat:
if len(x) != vnum: # 行数与列数做对比，检查邻接矩阵是否为合法的方阵
raise GraphError("Argument for 'Graph'.")
self._mat = [mat[i][:] for i in range(vnum)] # 拷贝
self._unconn = unconn
self._vnum = vnum # 邻接矩阵维数
def out_edges(self, vi):
if self._invalid(vi):
raise GraphError("{} is not a valid vertex.".format(vi))
return self._out_edges(self._mat[vi], self._unconn)
def get_edge(self, vi, vj):
if self._invalid(vi) or self._invalid(vj):
raise GraphError("{} or {} is not a valid vertex".format(vi, vj))
return self._mat[vi][vj]
def add_edge(self, vi, vj, val=1):
if self._invalid(vi) or self._invalid(vj):
raise GraphError("{} or {} is not a valid vertex".format(vi, vj))
self._mat[vi][vj] = val
def add_vertex(self):
raise GraphError("Adj-Matrix does not support 'add_vertex()'.")