Decode Ways

Decode Ways

Problem Statement

You are given a string

that represents a sequence of numbers from 1 to 9 repeated some number of times. A valid sequence is one where each number in the sequence is valid, and each number has a valid number of repeating preceding digits that it can be decoded as. A number that repeats times can be decoded as the number . If a number can be decoded as multiple values (e.g., '26'), it can only be decoded as one value in the sequence.

Rules and Constraints

• A number can have values from 1 to 9.
• The number in
  s
  must start with a character that can be decoded as a valid number.
• Each number in
  s
  must be valid and can be decoded as a sequence of preceding repeated digits.
• The string
  s
  is composed of only digits in the set [1-9].
• There will not be more than
  100
  digits in the string
  s
  .
• The function should return the total number of valid sequences that
  s
  can be decoded as.

Time/Space Complexity

The time complexity should be O(length of

), and the space complexity should be O(length of ), as only a single pass is needed to traverse the string and store the intermediate results if a dynamic programming approach is taken.

Example

Input: {"input_data":[1,2,3]} Output: [1,2,3]