def Floyd_Warshall(G, w):
inf = float("inf")
D = {u:{u:inf for u in G.sommets} for u in G.sommets}
Pred = {u:{u:None for u in G.sommets} for u in G.sommets}
for u in G.sommets:
for v in G.sommets:
D[u][v] = w[u][v]
Pred[u][v] = None if w[u][v] == inf else u
D_next = dcopy(D)
Pred_next = dcopy(Pred)
for x in G.sommets:
for u in G.sommets:
for v in G.sommets:
if D[u][x] + D[x][v] < D_next[u][v]:
D_next[u][v] = D[u][x] + D[x][v]
Pred_next[u][v] = Pred[x][v]
D = dcopy(D_next)
Pred = dcopy(Pred_next)
return (D, Pred)
def PCC1(G, w):
inf = float("inf")
D = {u:{u:inf for u in G.sommets} for u in G.sommets}
Pred = {u:{u:None for u in G.sommets} for u in G.sommets}
for u in G.sommets:
for v in G.sommets:
D[u][v] = w[u][v]
Pred[u][v] = None if w[u][v] == inf else u
D_next = dcopy(D)
Pred_next = dcopy(Pred)
for t in range(2, ceil(log(len(G.sommets) - 1, 2))):
for u in G.sommets:
for v in G.sommets:
for x in G.sommets:
if D_next[u][v] > D[u][x] + w[x][v]:
D_next[u][v] = D[u][x] + w[x][v]
Pred_next[u][v] = Pred[x][v]
D = dcopy(D_next)
Pred = dcopy(Pred_next)
return (D, Pred)
