0

AN implementation of Crohn(Крона) algorithm used in Scheduling theory, is it possible to change the data of the current index in a for loop in python? I have a code like so; link to the full code

#list1 is a 2d array
list1 = [[12, 3, 17], [14], [10, 12, 15]]


cond = 1
while cond:
    d = delta(sum_calc(list1))
#delta() finds the difference between the list with the highest sum
#and the list with the minimum sum, then returns the
#difference(d[0]), index_of_list_with_max_sum(d[1]), #index_of_list_with_min_sum(d[2])
#d = [23, 2, 1]

    if cond == 0:
        break
    else:
        for i in list1[d[1]]:
            if d[0] > i:
                move(list1[d[1]], list1[d[2]])
#move() moves the min element from list1, to list2
            else:
                cond = 0

what I am trying to do is, given an index, loop through the elements of that list, then check if num is greater than i (element), after that we do some operations, like moving the smallest element from the current list we are looping from, to another list. then we have some operations, after that I want to change the value of i, to something like

#the index might change
i = l[index]

the problem I am facing is that when I do that, it continues looping from the first index. Is there a way I can reset it, so that it starts looping from other elements?

I HAVE USED A WHILE LOOP, because I want the procedure to repeat itself and until d[0] !> i:

#since the list with the highest sum is list1[2], we got 2 from d,
#next step is to loop through the elements in that list and check if 
#there's an element which is less than d[0](the difference between max and min sum)


#expected results
#after first iteration
list1 = [[12, 3, 17], [14, 10], [12, 15]]
d = [8, 0, 1]

#after second iteration
list1 = [[12, 17], [14, 10, 3], [12, 15]]
d = [2, 0, 1]

#the problem is it stops here, I want it to calculate delta again then #repeat the process, but after debugging, i found that in the second #iteration i = 15, which the second element of the list, but it should #be like that.
Improve this question
2
  • 1
    Your description is very hard to follow. Given list1 = [[12, 3, 17], [14], [10, 12, 15]], please tell us what d will look like (we can't guess what delta() and sum_calc() do) and then say what you expect list2 to look like when the loop is finished. You also don't explain what move() does. As your code is presented, we can't even run it to see what it does. Please read this: stackoverflow.com/help/minimal-reproducible-example Commented Jun 13, 2021 at 10:02
  • sorry, one sec, lemme change. Commented Jun 13, 2021 at 10:06

1 Answer 1

Reset to default
1

Try to combine while loop with index ?

example:

lst = [1,2,3]

idx = 0
while idx < len(lst):
   print(lst[idx])
   idx += 1
   if idx == len(lst):
      # Reset index
      idx = 0

EDIT

After debugging I found your errors - You havent been assigning the new delta result to d where you have been referencing from your code thus you never got the new indexes

cond = True
idx = 0
while cond and idx < len(l[d[1]]):
    if d[0] > l[d[1]][idx]:
        move(l[d[1]], l[d[2]])
        s = sum_calc(l)
        d = delta(s)
        print("l =", l)
        print("s =", s)
        print("d =", d)
        print("")
        idx = 0
    else:
        cond = False
    idx += 1

Output:

l = [[12, 3, 17], [14, 10], [12, 15]]
s = [32, 24, 27]
d = [8, 0, 1]


l = [[12, 17], [14, 10, 3], [12, 15]] 
s = [29, 27, 27]
d = [2, 0, 1]
Improve this answer
Sign up to request clarification or add additional context in comments.

1 Comment

lemme see how I can incorporate it into my program

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.