An integer n is strictly palindromic if, for every base b between 2 and n - 2 (inclusive), the string representation of the integer n in base b is palindromic.
Given an integer n, return true if n is strictly palindromic and false otherwise.
A string is palindromic if it reads the same forward and backward.
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Example 1:
Input: n = 9
Output: false
Explanation: In base 2: 9 = 1001 (base 2), which is palindromic.
In base 3: 9 = 100 (base 3), which is not palindromic.
Therefore, 9 is not strictly palindromic so we return false.
Note that in bases 4, 5, 6, and 7, n = 9 is also not palindromic.
Example 2:
Input: n = 4
Output: false
Explanation: We only consider base 2: 4 = 100 (base 2), which is not palindromic.
Therefore, we return false.
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Constraints:
4 <= n <= 105
- Consider the representation of the given number in the base n - 2.
- The number n in base (n - 2) is always 12, which is not palindromic.
impl Solution {
pub fn is_strictly_palindromic(n: i32) -> bool {
let mut n = n;
let mut rev = 0;
while n > 0 {
rev = rev * 10 + n % 10;
n /= 10;
}
rev == n
}
}