Getting the wrong answer even though the expected output = output (HackerRank)

Question

I'm on HackerRank doing the zigzag sequence and although my output is the same as the expected output, it keeps saying I got the wrong answer. Had the same problem with my mock test earlier and am extremely frustrated by this since I couldn't finish the test on time because of it. Has anyone experienced anything similar on HackerRank?

my output:1 2 3 7 6 5 4 expected output: 1 2 3 7 6 5 4

My code is written below:

def findZigZagSequence(a, n):

    a.sort()
    mid = int((n + 1)/2) - 1
    a[mid], a[n-1] = a[n-1], a[mid]

    st = mid + 1 # 4ele = 5
    ed = n - 2 #5ele = 6
    while(st <= ed):
        a[st], a[ed] = a[ed], a[st]
        st = st + 1
        ed = ed - 1

    for i in range (n):
        if i == n-1:
            print(a[i])
        else:
            print(a[i], end = ' ')
    return

test_cases = int(input())
for cs in range (test_cases):
    n = int(input())
    a = list(map(int, input().split()))
    findZigZagSequence(a, n)

Answer 1

The tricky thing with some hackerrank solutions is that they are dependent on what the author expects to see.

For this case, the author wants us to just modify 3 lines. See my comments below.

def findZigZagSequence(a, n):
    a.sort()
    mid = int((n - 1)/2)             #line1
    a[mid], a[n-1] = a[n-1], a[mid]

    st = mid + 1
    ed = n - 2                       #line2
    while(st <= ed):
        a[st], a[ed] = a[ed], a[st]
        st = st + 1
        ed = ed - 1                  #line3

    for i in range (n):
        if i == n-1:
            print(a[i])
        else:
            print(a[i], end = ' ')
    return

test_cases = int(input())
for cs in range (test_cases):
    n = int(input())
    a = list(map(int, input().split()))
    findZigZagSequence(a, n)