How do you solve Strictly Palindromic Number on LeetCode?

Strictly Palindromic Number (LeetCode #2396) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(1) time complexity and O(1) space complexity. Key insight: In base n-2, the representation of n is always '12', which is not palindromic.

What is the time complexity of Strictly Palindromic Number?

The optimal solution for Strictly Palindromic Number runs in O(1) time and uses O(1) space. The time complexity is O(1) because we are returning a constant value without any loops or calculations.

What is the brute force solution for Strictly Palindromic Number?

The brute force approach for Strictly Palindromic Number is Brute Force, with O(n²) time complexity and O(1) space complexity. To determine if a number is strictly palindromic, we can convert it to every base from 2 to n-2 and check if the representation is a palindrome. This method is straightforward but inefficient. The optimal Optimal Solution approach improves this to O(1).

What algorithm or data structure is used to solve Strictly Palindromic Number?

Strictly Palindromic Number uses the following concepts: Math, Two Pointers, Brainteaser. The recommended patterns to study are: Mathematical properties, Base conversions.

What are the interview tips for Strictly Palindromic Number?

Always look for patterns or properties in the problem that can simplify your approach. If a brute-force solution seems too slow, think about the mathematical properties of the numbers involved. Practice explaining your thought process clearly, as this can help you identify flaws in your reasoning.

What are common mistakes when solving Strictly Palindromic Number?

Assuming that checking all bases is necessary when a direct observation can lead to a faster solution. Not recognizing that the problem constraints allow for a quick conclusion.

#2396

Strictly Palindromic Number

Medium

MathTwo PointersBrainteaserMathematical propertiesBase conversions

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(1)
Space	O(1)	O(1)

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Intuition

Time O(1)Space O(1)

We can deduce that n can never be strictly palindromic because in base n-2, the representation is always '12', which is not a palindrome. Thus, we can directly return false for any n >= 4.

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Algorithm

2 steps

1Step 1: Check if n is greater than or equal to 4.
2Step 2: Return false immediately since n in base n-2 is always '12'.

solution.py5 lines

1def is_strictly_palindromic(n):
2    return False
3
4# Example usage:
5print(is_strictly_palindromic(9))  # Output: False

ℹ

Complexity note: The time complexity is O(1) because we are returning a constant value without any loops or calculations.

1In base n-2, the representation of n is always '12', which is not palindromic.
2Strictly palindromic numbers do not exist for n >= 4.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.