diff --git a/shortest_path.py b/shortest_path.py
index bd1ba825c682c6d716ceffa8819a1ef890dc31a7..f3a95edd0880b444bc9a74d6455693c95e2befa3 100644
--- a/shortest_path.py
+++ b/shortest_path.py
@@ -1,16 +1,17 @@
-import numpy as np
import math
import argparse
import sys
-import os
-
-parser = argparse.ArgumentParser(description="LEPL1503 - Détection et correction d'erreurs")
-parser.add_argument("input_file", help="Nom du fichier contenant les données nécessaires")
-parser.add_argument("-f", help="Chemin vers le fichier de sortie", type=argparse.FileType("wb"), default=sys.stdout)
-parser.add_argument("-v", help="\"verbose\" mode: si ajouté, affiche des informations sur l'exécution du programme", action="store_true")
+parser = argparse.ArgumentParser(
+ description="LEPL1503 - Détection et correction d'erreurs")
+parser.add_argument(
+ "input_file", help="Nom du fichier contenant les données nécessaires")
+parser.add_argument("-f", help="Chemin vers le fichier de sortie",
+ type=argparse.FileType("wb"), default=sys.stdout)
+parser.add_argument(
+ "-v", help="\"verbose\" mode: si ajouté, affiche des informations sur l'exécution du programme", action="store_true")
args = parser.parse_args()
verbose = args.v
@@ -21,102 +22,101 @@ nb_edges = None
if verbose:
print(args, file=sys.stderr)
+
def get_file_infos(data):
- nb_nodes = int.from_bytes(data[0:4], "big",signed=True)
- nb_edges = int.from_bytes(data[4:], "big",signed=True)
- return nb_nodes,nb_edges
+ nb_nodes = int.from_bytes(data[0:4], "big", signed=True)
+ nb_edges = int.from_bytes(data[4:], "big", signed=True)
+ return nb_nodes, nb_edges
-def bellman_ford(table,s):
+
+def bellman_ford(table, s):
dist = [math.inf]*nb_nodes
- dist[s]=0
+ dist[s] = 0
path = [-1]*nb_nodes
for _ in range(nb_nodes-1):
for j in range(len(table)):
- a,b,cab = table[j][0],table[j][1],table[j][2]
- if(dist[a]!=math.inf and dist[b]>dist[a]+cab):
- dist[b]=dist[a]+cab
- path[b]=a
+ a, b, cab = table[j][0], table[j][1], table[j][2]
+ if (dist[a] != math.inf and dist[b] > dist[a]+cab):
+ dist[b] = dist[a]+cab
+ path[b] = a
for j in range(len(table)):
- a,b,cab = table[j][0],table[j][1],table[j][2]
- if(dist[a]!=math.inf and dist[b]>dist[a]+cab):
- print("Cycle négatif détecté")
- return -1, -1
+ a, b, cab = table[j][0], table[j][1], table[j][2]
+ if (dist[a] != math.inf and dist[b] > dist[a]+cab):
+ print("Cycle négatif détecté")
+ return -1, -1
return dist, path
-def get_path(dest, path,source):
+
+def get_path(dest, path, source):
r = [dest]
i = dest
- while(True):
- if (i ==source):
+ while (True):
+ if (i == source):
break
- r.insert(0,path[i])
+ r.insert(0, path[i])
i = path[i]
return r
-def get_max(dist,s):
+
+def get_max(dist, s):
max = -math.inf
n = s
for i in range(len(dist)):
- if(i!=s and dist[i]!=math.inf and dist[i]>=max):
+ if (i != s and dist[i] != math.inf and dist[i] >= max):
max = dist[i]
- n=i
- if(max==-math.inf):
- if(dist[s]!=math.inf and dist[s]>=max):
+ n = i
+ if (max == -math.inf):
+ if (dist[s] != math.inf and dist[s] >= max):
max = dist[s]
-
- return max,n
+
+ return max, n
+
+
if __name__ == "__main__":
-
+
with open(args.input_file, "rb") as input_file:
binary_data = input_file.read()
nb_nodes, nb_edges = get_file_infos(binary_data[:8])
if verbose:
- print("Number of nodes :", nb_nodes, ", number of links :", nb_edges)
-
+ print("Number of nodes :", nb_nodes,
+ ", number of links :", nb_edges)
+
binary_data = binary_data[8:]
table = []
if output_fd == sys.stdout or output_fd == sys.stderr:
print(nb_nodes)
-
- else :
+
+ else:
output_fd.write(nb_nodes.to_bytes(4, "big"))
-
for i in range(nb_edges):
- a = int.from_bytes(binary_data[i*16:i*16+4],"big",signed=True)
- b = int.from_bytes(binary_data[i*16+4:i*16+8],"big",signed=True)
- cab = int.from_bytes(binary_data[i*16+8:i*16+12],"big",signed=True)
- cba = int.from_bytes(binary_data[i*16+12:i*16+16],"big",signed=True)
- if (cab !=0):
- l1 = [a,b,cab]
- table.append(l1)
- if(cba!=0):
- l2 = [b,a,cba]
- table.append(l2)
+ a = int.from_bytes(binary_data[i*12:i*12+4], "big", signed=True)
+ b = int.from_bytes(binary_data[i*12+4:i*12+8], "big", signed=True)
+ cab = int.from_bytes(
+ binary_data[i*12+8:i*12+12], "big", signed=True)
+ l1 = [a, b, cab]
+ table.append(l1)
for i in range(nb_nodes):
- dist, path = bellman_ford(table,i)
- if dist ==-1 : break
-
+ dist, path = bellman_ford(table, i)
+ if dist == -1:
+ continue
+
if output_fd == sys.stdout or output_fd == sys.stderr:
print("source : "+str(i))
- d,n = get_max(dist,i)
- print("destination : "+ str(n))
- print("cout : "+ str(d))
- p = get_path(n,path,i)
+ d, n = get_max(dist, i)
+ print("destination : " + str(n))
+ print("cout : " + str(d))
+ p = get_path(n, path, i)
print("nombre de noeuds : "+str(len(p)))
print("chemin : "+" ".join(str(x) for x in p))
print("-----------------------")
-
- else :
+
+ else:
output_fd.write(i.to_bytes(4, "big"))
- d,n = get_max(dist,i)
- output_fd.write(n.to_bytes(4, "big",signed=True))
- output_fd.write(d.to_bytes(4, "big",signed=True))
- r = get_path(n,path,i)
- output_fd.write(len(r).to_bytes(4, "big",signed=True))
- for j in range(len(r)) :
+ d, n = get_max(dist, i)
+ output_fd.write(d.to_bytes(4, "big", signed=True))
+ output_fd.write(n.to_bytes(4, "big"))
+ r = get_path(n, path, i)
+ output_fd.write(len(r).to_bytes(4, "big", signed=True))
+ for j in range(len(r)):
output_fd.write(r[j].to_bytes(4, "big"))
-
-
-
-
\ No newline at end of file