此代码的目的是创建连接每个点的最短路径。我试图在Python中实现Kruskals算法，但是有一个问题，它发生在调用函数findSet（x）时。似乎程序进入无限循环。我试图打印x，x.dad和x.dad.dad和x在关键时刻返回初始x。我真的不知道问题出在哪里。
class Point:
def __init__(self,x = None, y = None):
self.x = x
self.y = y
self.dad = None
self.rank = None
class Edge:
def __init__(self, firstPoint = None, secondPoint = None, value = None):
self.firstPoint = firstPoint
self.secondPoint = secondPoint
if self.firstPoint != None and self.secondPoint != None:
self.value = abs(firstPoint.x-secondPoint.x) + abs(firstPoint.y - secondPoint.y)
else:
self.value = float("inf")
def makeSet(node):
node.dad = node
node.rank = 0
def findSet(x):
print x, x.dad,x.dad.dad
if x == x.dad:
return x
x.dad = findSet(x.dad)
return x.dad
def unionSet(node1,node2):
root1 = findSet(node1)
root2 = findSet(node2)
if root1.rank < root2.rank:
root1.dad = root2
if root1.rank > root2.rank:
root2.dad = root1
else:
root2.dad = root1
root1.rank += 1
def merge(A, p, q, r):
L = A[p:q+1]
R = A[q+1:r+1]
infinite = Edge()
L.append(infinite)
R.append(infinite)
temp = []
i = 0
j = 0
for k in range(p,r+1):
if L[i].value <= R[j].value:
temp.append(L[i])
i += 1
else:
temp.append(R[j])
j += 1
A[p:r+1] = temp
def mergeSort(A,p,r):
A2 = A
if p < r:
q = int((p+r)/2)
mergeSort(A2, p, q)
mergeSort(A2, q+1, r)
merge(A2, p, q, r)
def readPoint(A):
temp = []
for i in range(0,len(A), 2):
tempPoint = Point(A[i],A[i+1])
makeSet(tempPoint)
temp.append(tempPoint)
return temp
def calculateEdges(A):
tempArray = []
for i in range(0,len(A)):
for j in range(i+1,len(A)):
edge = Edge(A[i], A[j])
tempArray.append(edge)
return tempArray
def Kruskal(N, E):
mergeSort(E,0,len(E)-1)
j = 0
i = 0
total = 0
while j < N:
if findSet(E[i].firstPoint) != findSet(E[i].secondPoint):
unionSet(E[i].firstPoint,E[i].secondPoint)
j += 1
total += E[i].value
if i < len(E) - 1:
i += 1
return total
Ar = readPoint([18, 2, 99, 68])
E = calculateEdges(Ar)
print Kruskal(len(Ar),E)