2 docs tagged with "Combinatorics"

You are given a 0-indexed integer array nums, where nums[i] is a digit between 0 and 9 (inclusive).

You are given a string s consisting of digits. Perform the following operation repeatedly until the string has exactly two digits:For each pair of consecutive digits in s, starting from the first digit, calculate a new digit as the sum of the two digits modulo 10. Replace s with the sequence of newly calculated digits, maintaining the order in which they are computed. Return true if the final two digits in s are the same; otherwise, return false.