我需要什么语法来正确地遍历此列表？

Question

Looping through a list, trying to use the list in an if statement, but receiving error messages about syntax and how lists must be integers or slices and not tuples. Trying to understand what went wrong.

I'm working on a challenge from Hackerrank that I am just about done with, but I am a bit stuck. Essentially, I have a list called "pages", referring to the pages in a workbook as specified in the description of the challenge linked here:

https://www.hackerrank.com/challenges/lisa-workbook/problem

pages is a list where each element represents 1 page in the workbook and the elements inside these elements represent the numbers of the problems on that page (ie: page 1 has problems 1, 2, and 3 for chapter 1 while page 2 has problem 4 for that chapter). The challenge asks us to count the total number of problems in the workbook whose problem numbers match the page number that they are found on.

My first instinct was to iterate through the pages, then iterate through the problems on that page and add to a counter special_probs anytime the iterating variable for the problems on the page matched the iterating variable for that page. This is all done in the bottom 4 lines of code. However, calling the current page we are on in the nested for loop is giving me some issues. It is likely something super easy or silly, but I'd appreciate your help in understanding why I am not allowed to do it the way I have it and what I need to do differently in order to get it to work as intended. If you need more information or context please let me know. Thank you!

(I also commented the hell out of my code in this particular instance. If it is distracting, I can cut them out.)

n = 4 #total number of chapters (there are 5, but index "z" starts @ 0)
k = 3 #maximum number of problems allowed per page
arr = [4, 2, 6, 1, 10] #example array listing the # of problems per chapter
pages = [0] #total number of pages in workbook (added 0 so pages start on 1)
z = 0 #chapter index counter
prob_increment = 0 #helps properly number multi-page chapters
special_probs = 0 #counter for all special problems 

while z <= n: #indexing through chapters, filling 1 at a time with problems
    pages_in_chapter = -(-arr[z]//k) #no more than k problems per page 
    if arr[z] <= k: #if all problems in the chapter fit on 1 page...
        new_page_proto = list(range(arr[z])) 
        new_page = [y+1 for y in new_page_proto] 
        pages.append(new_page) #adds completed page to the workbook's pages
    else: #for chapters with more problems than k
        chapter_probs_count = arr[z] 
        while chapter_probs_count > k: #fill pages until we have =<k left 
            new_page = list(range(k)) #create new page, add k problems
            new_page = [x+prob_increment*3 for x in new_page] #pages <1 in ch
            new_page = [y+1 for y in new_page] #fix offset again
            pages.append(new_page) #adds completed page to workbook's pages
            prob_increment = prob_increment + 1 #increase to denote new page
            chapter_probs_count = chapter_probs_count - k 
        new_page = list(range(chapter_probs_count)) #adds remaining probs <k
        new_page = [x+prob_increment*3 for x in new_page] 
        new_page = [y+1 for y in new_page] #fix offset again
        pages.append(new_page) #add the final page of the chapter to pages
    z = z + 1 #increment z & repeat the page-adding process for n chapters
    prob_increment = 0; #reset the incrementer when starting new chapter  

for y in enumerate(pages): #search for special problems 1 page at a time
    for x in enumerate(pages(y)) #compare each problem on page to page # 
        if x == pages(y): #if page 
            special_probs = special_probs + 1 

Variable explorer reports:

pages = [0, [1,2,3], [4], [1,2], [1,2,3], [4,5,6], [1], [1,2,3], [4,5,6], [7,8,9], [10]]

arr = [4,2,6,1,10]

new_page = [10]

new_page_proto = [0]

z = 5

Current error message:

File "C:/Users/the_h/.spyder-py3/temp.py", line 43 for x in enumerate(pages(y)) #compare each problem on page to page # ^ SyntaxError: invalid syntax

Answer 1

I'm not sure wheter I understood the context enough but here is what I would do. I would try to have something like this :

all_probs = [[[1,2,3],[4],[5]],[[1,2],[3,4,5]],[[1],[2],[3],[4,5]],...]

in this example the first element all_probs[0] is the first chapter. Then, the element all_probs[0][0] is the first page. We see that the first page contains the problems 1,2 and 3 for example.

Then, what you would have to do would be this :

counter = 0
for i in all_probs:               #selects a chapter
    for j in range(len(i)):       #goes through the pages
        for k in i[j]:            #for each problem on that page
            if k == j+1:          #if the prob nbr matches the page nbr
                counter+=1        #increment the counter