Problem1: (https://leetcode.com/problems/ugly-number-ii/)
Current Statement Write a program to find the n-th ugly number.
Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.
Example:
Input: n = 10
Output: 12
Explanation: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the first 10 ugly numbers.
Note:
-
1 is typically treated as an ugly number.
-
n does not exceed 1690.
Given a string s, find the longest substring in s which is a palindrome.
Example 1:
Input: "bababd"
Output: "babab"
Note: "aba" is also a valid answer.
Example 2:
Input: "cbbd"
Output: "bb"