class SP(object):
def __init__(self, G, s):
self.G = G
self.s = s
self.h = Heap(self.G.V())
for i in range(self.G.V()):
self.h.insert(i, self.G.adjmat[self.s][i])
self.adjlist = [[0, 0, 0] for i in range(self.G.V())]
self.count = 0
def disttov(self, v):
adjmat = self.G.adjmat
n = self.G.V()
if adjmat[self.s][v] != -1:
return adjmat[self.s][v]
return 100000
def hasPathtov(self, v):
dis = self.disttov(v)
if dis != 100000:
return True
return False
def display(self):
print("shortest path from source ", self.s)
for x in self.adjlist:
print("Vertex: ", x[0], " Distance: ", x[1], " Predecessor: ",
x[2])
def dijkstraSP(self):
for i in range(self.G.V()):
vert = self.h.DeleteMin()
self.adjlist[self.count][0] = vert[0]
self.adjlist[self.count][1] = vert[1]
self.relax(vert[0])
self.count += 1
self.display()
def relax(self, v):
for adjedge in self.G.adj(v):
if (adjedge.weightv() + self.G.adjmat[self.s][v]
) < self.G.adjmat[self.s][adjedge.tov()]:
self.h.DecreaseKey(
adjedge.tov(),
adjedge.weightv() + self.G.adjmat[self.s][v])
self.adjlist[adjedge.tov()][2] = v
from Heap import Heap heap = Heap() # heap.BuildHeap([9,5,6,2,3]) heap.Insert(9) heap.Insert(5) heap.Insert(6) heap.Insert(2) heap.Insert(3) heap.Print() print(heap.DeleteMin()) heap.Print() print(heap.DeleteMin()) heap.Print() print(heap.DeleteMin()) heap.Print()
