def test_estimate_value_1():
input_text = "4 11\n8 4\n10 5\n15 8\n4 3\n"
choice = [1,1,0]
kp = KnapsackProblemData(input_text)
num_chosen = len(choice)
current_weight = np.sum(np.multiply(kp.weights[0:num_chosen],np.array(choice)))
current_value = np.sum(np.multiply(kp.values[0:num_chosen],np.array(choice)))
# value vector [ 10 8 15 4 ]
# weight vector [ 5 4 8 3 ]
# choice gets weight 5+4 = 9 with remaining capacity 2
# choice gets value 10+8 = 18
# we can take 2/3 of item 4, giving us added value of (2/3)*4 = 2.67
# estimated value == 20.67
estimated_value = estimate_value(kp,choice,current_weight,current_value)
assert choice == [1,1,0] # choice should not mutate
assert estimated_value == 18 + (2*4)/float(3)
def test_estimate_value_2():
input_text = "4 11\n8 4\n10 5\n15 8\n4 3\n"
choice = [0,0]
kp = KnapsackProblemData(input_text)
num_chosen = len(choice)
current_weight = np.sum(np.multiply(kp.weights[0:num_chosen],np.array(choice)))
current_value = np.sum(np.multiply(kp.values[0:num_chosen],np.array(choice)))
# value vector [ 10 8 15 4 ]
# weight vector [ 5 4 8 3 ]
# choice gets weight 0 with remaining capacity 11
# choice gets value 0
# we take all of item 3
# value = 15
# weight = 8
# we can take all of item 4, giving us added value of 4
# estimated value == 19
estimated_value = estimate_value(kp,choice,current_weight,current_value)
assert choice == [0,0] # choice should not mutate
assert estimated_value == 19
