plz check the updated program

Greedy algorithm prob. in pyhton/Fractional Knapsack/knapsck1.py

@@ -1,29 +1,55 @@
-n,W = map(int, input().split(" "))
-maxvalue = 0.000
-nval = 0.000
-value = list()
-weight = list()
-ratio = list()
-for num in range(n):
- v,w = map(float, input().split(" "))
- value.append(v)
- weight.append(w)
- ratio.append(float(v/w))
- #ratio.sort(reverse = True)
-while W>0:
- try:
- num = ratio.index(max(ratio))
- except:
- break
- if W == weight[num]:
- maxvalue+=value[num]
- break
- elif W>weight[num]:
- maxvalue+=value[num]
- W-=weight[num]
- ratio.remove(max(ratio))
- elif W <weight[num]:
- nval = float((value[num]/weight[num])*W)
- maxvalue+=nval
- break
-print("{:.4f}".format(maxvalue))
+## Process the data to divide knapsack dimension/capacity and the available items
+
+def f_knap_preparation(x):
+ knap = {"items":x[0], "weights":x[1]}
+ elements = x[2:]
+ count = len(elements)/2
+ entries = {"items":list(), "weights" : list() }
+ for i in range( len(elements)):
+ if (i % 2 == 0):
+ entries['items'].append(elements[i])
+ else:
+ entries['weights'].append(elements[i])
+
+ values = [x/y for x,y in zip(entries['items'],entries['weights'])]
+
+ return(knap, entries, values, count)
+
+## Main function to use the processed data from 'f_knap_preparation()' to optimize the item inclusion in the knapsack
+
+def f_knap_main(x1):
+ if(len(x1) %2 != 0):
+ print('There must be some number missing in your input. Try again !!')
+ else:
+ knap, entries, values, count = f_knap_preparation(x1)
+ capacity = knap['weights']
+ items = knap['items']
+ result ={'items':list(), 'values':list()}
+ while capacity and items and count != 0:
+
+ indexer = values.index(max(values))
+ maxvalue = entries['items'][indexer]
+ maxweight = entries['weights'][indexer]
+
+ if(maxweight <= capacity):
+ capacity = capacity - maxweight
+ result['items'].append(indexer + 1)
+ result['values'].append(maxvalue)
+ else:
+ result['values'].append((capacity/maxweight) * maxvalue)
+ result['items'].append(indexer + 1)
+ capacity = capacity - (capacity * (capacity/maxweight))
+ count = count - 1
+ entries['items'].remove(entries['items'][indexer])
+ entries['weights'].remove(entries['weights'][indexer])
+ values.remove(values[indexer])
+ total = sum(result['values'])
+ print('Total value obtained from the items is ' + str(total) + " from items " + str(result['items']) + " with following values " + str(result['values']))
+
+ return(result) 
+
+## This code initiates the script and prompts for the user-input.
+
+numbers = list(raw_input('Enter the values and weights after knapsack attributes placing spaces between numbers : ').split(' '))
+user_num = [int(x) for x in numbers]
+f_knap_main(user_num)