Во фрипаскале кейс не принимает стринги, насколько я помню. Попробуйте через ифы: if (a[i] = 'a1') or (a[i] = 'a8') и тд.

I understood. The right way is not at converting entered binary number to decimal.

Perhaps, you don't sort the result?

The same problem! What is the Test 2?

solved. you should calculate everything in int64 not doubles

Never mind, found it-it could be when no item is marked in requirement string.

Can I solve this problem by natural merge sort?

I solved it via following approach, split array by incrementing sub sequencies (incrementing by 1) and join it back after sorting.

For example 5 1 3 2 4
Will be splited by (5) (1 2) (3 4).
After sort it by first element
(5) (1 2) (3 4) => (1 2) (3 4) (5)
After that all sequences on odd position gos to way #1 and all other to way #2
We will have (1 2 5) in way#1 and (3 4) in way#2 and trust order in array.
we will have (5 1 2) in way#1 and (3 4) in way#2.
And after join in will be (5 1 2 3 4).

Iterate such approach till not get (1 .. N)

Example of output for N=16 and decreasing array.
4
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
15 13 11 9 7 5 3 1 16 14 12 10 8 6 4 2
13 9 5 1 14 10 6 2 15 11 7 3 16 12 8 4
9 1 10 2 11 3 12 4 13 5 14 6 15 7 16 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

const long double eps=1e-12;

using long double...

what's the principle of the solution?
i've tried to construct laser-lines one after another with the smallest distance, and then to find dots of intersections line[i] and line[i+1], then find intersection of line[i+1] and line[i+2] and after that find the distance between dot[1] and dot[2], dot[2] and dot[3] and so on. But that's a big problem: line[i] can intersect line[i+1] in dot[1], that can later occur outside of the figure, formed with intersects of line[i+1000] and line[i+1001]. What's the solution?

I got WA #7 as well.. not sure what went wrong anyone has the input n and expected output? Thanks

Got AC. Made a mistake in printing long number — need no print leading zeros for non-top parts of number