partial

python/foobar/three/interrogation.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+# Foreach minion, x[0] = time, x[1]/x[2] = probability of response.
+inputs = [ [[5, 1, 5], [10, 1, 2]], [[390, 185, 624], [686, 351, 947], [276, 1023, 1024], [199, 148, 250]] ]
+solutions = [ [1,0], [2,3,0,1] ]
+
+minions = inputs
+
+def answer(minions):
+    """Calculate the optimal interrogation order, providing the answer in the shortest time"""
+    """ T[1] + (1-P[1])*T[2] + (1-P[1])(1-P[2])*T[3]"""
+
+    optimal = [ [], 0 ]
+
+    for i,minion in enumerate(minions):
+        recurse_minions([i],minions,1-probabilityOf(minion),minion[0])
+
+    return optimal[0]
+
+def recurse_minions(used,minions,pn,t):
+    global optimal
+    for i, minion in enumerate(minions):
+        try:
+            used.index(i)
+            next
+        except ValueError:
+            # Counterintuitive warning: ValueError indicates that 'i' does not
+            # exist within the list of currently used minions.  This means that
+            # we process this minion.  Lack of ValueError indicates that this
+            # minion has already been processed.
+            p = pn*(1-probabilityOf(minion))
+            time = t + (pn*minion[0])
+            curr = used+[i]
+            if len(curr) == len(minions):
+                if len(optimal[0])>0:
+                    if time < optimal[1]:
+                        optimal[0] = curr
+                        optimal[1] = time
+            else:
+                recurse_minions(curr,minions,p,time)
+
+def probabilityOf(minion):
+    return ((1.0*minion[1])/minion[2])
+
+for i in range(0,len(solutions)):
+    print answer(inputs[i])
+    print solutions[i]