What’s wrong?

Question

The entered sequence in reverse order should be ascending, why doesn't the code output anything?
https://code.sololearn.com/cduo0qPffVQj/?ref=app

Answer 1

For example, if input is 12345 then reversed is 54321
counter = 0
digit = 5 at first iteration so in inner while loop :
digit < counter is false so by else counter = digit so counter = 5, iterating inner loop digit < counter false so by else counter = digit.. => counter = 5
...
.. This will be repeated for ever and it's an infinite loop...
Hope it clears..

Answer 2

Nastya ,

an other approach could be to compare the input sequence of digits against a sorted sequence:

> split input string to a list of numbers:
... = list(map(int, list(input())))
> input '123':
list(input()) => ['1', '2', '3']
> now we map the int constructor to each element of the list:
list(map(int, ['1', '2', '3'])) => [1, 2, 3]

> now we can sort the resulting list from above and compare it against the unsorted list.

digits = list(map(int, list(input())))
if digits == sorted(digits):
print('No')
else:
print('Yes')

Answer 3

Smith Welder ,

i suppose that you have not tested my code.

for input: 1245, the output is 'NO'

Answer 4

Benjamin Kiplagat ,

it is better for you to start your own post, otherwise poeple will not get aware of you. please also include your current code in the post.

Answer 5

Smith Welder,
number = list(map(int, input()))
print("YES"if all(number[i] >= number[i+1] for i in range(len(number)-1)) else "NO")

Answer 6

I guess task is to check all digits should be in ascending order.

There is no need of inner while loop in your code as you need to traverse sequencly in one time.
Use index positions instead of values. So you can check
list[0] > list[1] , list[1] > list[2], ..
Without indexes, you can't get next value.

As you dont need original value, replace original with
number = numbers[::-1] #reversed list numbers
Then use
for i in range(len(numbers)) :
...

Answer 7

Thanks a lot, but I want to understand my mistake, why didn't my code work correctly? 🥺🥺

Answer 8

THANK YOU
https://code.sololearn.com/cduo0qPffVQj/?ref=app

Answer 9

Well done.Good logic.. 👏👍

Answer 10

The while loop is infinite.
What are you trying? Any example input and expected output?

Answer 11

This code has a condition that breaks the loop 🤔
For example:
input - 12345 -> output - NO
input - 5321 -> output - YES

Answer 12

you cant use this operator ">" or this operator "<" to compire sequence, cause you'll get "yes" for this 54321 and you'll get "yes" for wrong sequence too , like this 5421. So you need use operator "==" for your solution and compire every number in sequence. You not need to use some flags, you can use function all() for that..
Your solution can be look like this:
number = list(map(int, input()))
print("YES"if all(number[i] == number[i+1]+1 for i in range(len(number)-1))else "NO")

Answer 13

Nastya,
number = list(map(int, input()))
print("YES"if all(number[i] >= number[i+1] for i in range(len(number)-1)) else "NO")
this wrong too, try to input like this 5421 and you'll get "yes", cause here you are compire great or equals between two numbers, but dont check out sequence..
As i wrote, you can see that compire all numbers and chek out all sequence, plus you not need call reversed() function.
Look at this again:
number = list(map(int, input()))
print("YES"if all(number[i] == number[i+1]+1 for i in range(len(number)-1))else "NO")

Answer 14

Smith Welder,

This will be correct, because I need to check not that the numbers are in order, but that they are reversed in ascending order and each subsequent one is NOT less than the previous one

For example:
input - 12345 -> output - NO
input - 5321 -> output - YES

Answer 15

Lothar,
function sorted() cant work right with sequence, cause you'll get "yes" whatever right sequence or not..
12345 - "yes"
but for wrong sequence will be "yes" too
1245 - "yes"

Answer 16

May anyone help me to solve a problem