The check digit is used to confirm the initial digits of the card number. The benefits of using a checksum is that it prevents casual attempts to invent credit card numbers, as only one in ten will be valid.
Length (adj). the longest, or longer, dimension of any object, in distinction from breadth or width; extent of anything from end to end; the longest line which can be drawn through a body, parallel to its sides; as, the length of a church, or of a ship; the length of a rope or line.
Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000. Example: Input: babad Output: bab Note: aba is also a valid answer. Example: Input: cbbd Output: bb. Subscribe to see which companies asked this question.