Python implementation of the knapsack problem.

other/knapSack.py

@@ -0,0 +1,52 @@
+"""
+Jeffery Russell
+12-1-18
+"""
+
+
+def knapsack(V, W, capacity):
+    """
+    Dynamic programming implementation of the knapsack problem
+
+    :param V: List of the values
+    :param W: List of weights
+    :param capacity: max capacity of knapsack
+    :return: List of tuples of objects stolen in form (w, v)
+    """
+    choices = [[[] for i in range(capacity + 1)] for j in range(len(V) + 1)]
+    cost = [[0 for i in range(capacity + 1)] for j in range(len(V) + 1)]
+
+    for i in range(0, len(V)):
+        for j in range(0, capacity + 1):
+            if W[i] > j:  # don't include another item
+                cost[i][j] = cost[i -1][j]
+                choices[i][j] = choices[i - 1][j]
+            else:  # Adding another item
+                cost[i][j] = max(cost[i-1][j], cost[i-1][j - W[i]] + V[i])
+                if cost[i][j] != cost[i-1][j]:
+                    choices[i][j] = choices[i - 1][j - W[i]] + [(W[i], V[i])]
+                else:
+                    choices[i][j] = choices[i - 1][j]
+    return choices[len(V) -1][capacity]
+
+
+def printSolution(S):
+    """
+    Takes the output of knapsack and prints it in a
+    pretty format.
+
+    :param S: list of tuples representing items stolen
+    :return: None
+    """
+    print("Thief Took:")
+    for i in S:
+        print("Weight: " + str(i[0]) + "\tValue: \t" + str(i[1]))
+
+    print()
+    print("Total Value Stolen: " + str(sum(int(v[0]) for v in S)))
+    print("Total Weight in knapsack: " + str(sum(int(v[1]) for v in S)))
+
+
+values = [99,1,1,1,1, 1,1]
+weights = [5,1,2,3,4,5,1]
+printSolution(knapsack(values, weights, 6))