def singleSourceShortest(G, src):
"""
Given graph G return dictionary of shortest paths to other vertices
from vertex src. All vertices in G must be drawn from the range 0..n-1
and src must also be from same range.
"""
# Initialize dist[] matrix to be Infinity for all but src
infinity = sys.maxsize
n = 0
dist = {}
for v in range(len(G)):
n += 1
dist[v] = infinity
dist[src] = 0
# optimized construction for BinaryHeap
pq = BinaryHeap(n, src, infinity)
while not pq.isEmpty():
u = pq.pop()
for v,weight in G.neighbors(u):
newLen = dist[u] + weight
if newLen < dist[v]:
pq.decreaseKey(v, newLen)
dist[v] = newLen
return dist
def singleSourceShortest(G, src):
"""
Given graph G return dictionary of shortest paths to other vertices
from vertex src. All vertices in G must be drawn from the range 0..n-1
and src must also be from same range.
"""
# Initialize dist[] matrix to be Infinity for all but src
infinity = sys.maxsize
n = 0
dist = {}
for v in range(len(G)):
n += 1
dist[v] = infinity
dist[src] = 0
# optimized construction for BinaryHeap
pq = BinaryHeap(n, src, infinity)
while not pq.isEmpty():
u = pq.pop()
for v, weight in G.neighbors(u):
newLen = dist[u] + weight
if newLen < dist[v]:
pq.decreaseKey(v, newLen)
dist[v] = newLen
return dist
