first commit

09/part1.py

@@ -0,0 +1,61 @@
+#!/usr/bin/python
+
+import re
+
+RE_DISTANCE = re.compile(r'^(.*) to (.*) = (\d+)$')
+
+
+class Town:
+
+    def __init__(self, name):
+        self.name = name
+        self.distance = dict()
+
+    def addDistance(self, town, distance):
+        self.distance[town] = distance
+
+
+def read_file(filename):
+    file = open(filename, 'r')
+    while True:
+        line = file.readline()
+        if not line:
+            break
+        yield line
+
+
+def computePossiblePaths(town, neighbours, maxTowns, visited, journey):
+    visited.append(town)
+    if len(visited) == maxTowns:
+        print "%010d %s" % (journey, ",".join(visited))
+        visited.pop()
+        return
+    for nei in neighbours[town].distance.keys():
+        if nei in visited:
+            continue
+        distance = neighbours[town].distance[nei]
+        journey += distance
+        computePossiblePaths(nei, neighbours, maxTowns, visited, journey)
+        journey -= distance
+    visited.pop()
+
+
+def main():
+    towns = dict()
+    for line in read_file('input'):
+        match = re.search(RE_DISTANCE, line)
+        if not match:
+            print "wrong operation syntax"
+        if match.group(1) not in towns:
+            towns[match.group(1)] = Town(match.group(1))
+        if match.group(2) not in towns:
+            towns[match.group(2)] = Town(match.group(2))
+        towns[match.group(1)].addDistance(match.group(2), int(match.group(3)))
+        towns[match.group(2)].addDistance(match.group(1), int(match.group(3)))
+
+    for town in towns.keys():
+        print "Starting point: %s" % (town)
+        computePossiblePaths(town, towns, len(towns.keys()), [], 0)
+
+if __name__ == "__main__":
+    main()