[Python] Squares of a Sorted Array: why sorted() method is faster than O(n) method? [closed]

I am working on LeetCode algorithm problem 977. Squares of a Sorted Array.

Why are the submissions using the built-in method sorted faster than my O(n) traversal method as below?

The input is a sorted (non-decreasing order) list with integers.

Sample 208 ms submission:

class Solution:
def sortedSquares(self, A: List[int]) -> List[int]:
return sorted(x*x for x in A)


My 260 ms submission:

class Solution:
def sortedSquares(self, A: List[int]) -> List[int]:
start = 0
end = len(A)-1

B = []

while start <= end:
if abs(A[start]) >= abs(A[end]):
B.append(A[start] * A[start])
start += 1
else:
B.append(A[end] * A[end])
end -= 1
B.reverse()
return B

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