Python find() function 如何在下面的代码中工作？

Question

i was going through the solution for beautiful matrix(ques of CodeForces).Can you explain what is happening in the below code?

l=[2,1,0,1,2]
for i in l:
    s=input()
    if "1" in s:print(i+l[s.find("1")//2])

Answer 1

The code gives an error. The result is shown below:

Traceback (most recent call last): File "main.py", line 3, in s=input() EOFError: EOF when reading a line

Answer 2

You have a list of numbers. Then your iterating through each one such that i = 2, i = 1, .. etc. If the user input is 1 then it will print off whatever i currently is plus whichever input index has the 1 divided by 2 and floored.

I would probably format like this

l=[2,1,0,1,2]
for i in l:
    s=input()
    if "1" in s:
        print(i+l[s.find("1")//2])

Answer 3

The code iterates through the given list of numbers, l. Then, for each of the elements in this list, it will ask the user for an input. If the user input has a 1 in it, it will print the sum of the list element + the floored division by 2 (the // operators) of the index of the FIRST occurence in the user-inputted value. Note that the indexes start counting from 0. The floored division means a divison without commas, rounding to the nearest number on the lower side (eg 2.7 will be rounded to 2)

Answer 4

The question is basically this:

How many steps are required to move a '1' to the center of a 5x5 matrix (The matrix has all values as '0' except a single position where it is '1')

The solution provided above is something like this:

//(2,2) is the final (center) position

l=[2,1,0,1,2] // l denotes the number of steps required if '1' was found in the ith row (for instance, 2 in the 0th row indicates that two steps would be required to move from 0th row to 2nd row)

for i in l:
    s=input() // s contains values for the ith row
    // If a "1" is present in the ith row, it would mean you need to move i position up/down to reach the center row
    // Let k = s.find("1"), k here gives the column in which the "1" is present. So, an additional k//2 steps would be required to move across the columns to reach the center
    // hence i (for row movement) + k(for column movement) steps would be required to reach the center
    if "1" in s:
        print(i+l[s.find("1")//2])