#!/usr/bin/env python3
from topsort import topsort
from math import inf

def shortest(root,G):
    n = len(G);
    dist = [inf] * n
    dist[root] = 0

    (rank,order) = topsort(G)
    In = inbound(G)

    for j in range(rank[root]+1,n):
        v = order[j]
        for (prev,w) in In[v]:
            if w+dist[prev] < dist[v]:
                dist[v]=w+dist[prev]
    return dist

def inbound(G):
    n = len(G)
    In = [ [] for j in range(n) ]
    for v in range(n):
        for (u,w) in G[v]:
            In[u].append((v,w))
    return In

if __name__ == "__main__":

    # [(dest,weight),...]    # from
    Graph = [ [(2,4),(3,4),(5,3)],
              [(0,4),(2,1),(3,3)],
              [(3,2),(4,4)],
              [(4,6)],
              [],
              [(4,5)] ]

    d = shortest(0,Graph)
    print(d)