"""

Name: dijkstra - Dijkstra for the Single Source Shortest Path problem

Description: dijkstra applies the Dijkstra algorithm for the Single Source Shortest Path problem.

Author: Eugen Sawin <sawine@me73.com>

"""

def main():

    args = parse_arguments()

    s = args.source

    raw_graph = args.graph

    graph = [e.strip(' ,(').split(',') for e in raw_graph.split(')')]

    graph = [(e[0].strip(), e[1].strip(), int(e[2].strip())) for e in graph if len(e) == 3]

    distances = dijkstra(s, create_graph(graph))

    for (v, d) in distances.iteritems():

        print '%s: %i' % (v, d)

def create_graph(desc):

    vertices = set([e[0] for e in desc]) 

    vertices = vertices.union([e[1] for e in desc])

    edges = dict(zip([(v1, v2) for (v1, v2, _) in desc], [c for (_, _, c) in desc]))

    return (vertices, edges)    

from heapq import *

def dijkstra(s, (vertices, edges)):

    inf = sum(edges.itervalues()) + 1

    dist = dict([(v, inf) for v in vertices])

    dist[s] = 0

    u = []

    for (v, d) in dist.iteritems():

        heappush(u, (d, v))

    active = vertices

    while len(u) and len(active):

        (_, node) = heappop(u)

        if node in active:

            active.remove(node)

            for (v1, v2) in [e for e in edges.iterkeys() if e[0] == node]:

                c = edges[(v1, v2)]

                if dist[v2] > dist[v1] + c:

                    dist[v2] = dist[v1] + c

                    heappush(u, (dist[v2], v2))

    return dist                    

from argparse import ArgumentParser

def parse_arguments():

    parser = ArgumentParser(description='Applies the Dijkstra algorithm for the single source shortest path problem.')

    parser.add_argument('graph', help='sequence of (u, v, c(u,v))')

    parser.add_argument('source', help='source vertex')

    return parser.parse_args()

if __name__ == "__main__":

    main()