Ribbon runs: Positive proof strip
Inputs
line is text. A character is one letter, digit, space, or punctuation mark.
Your tasks
- Create a list
runLengths. A run is a group of matching characters next to each other. End a run only when the character changes or the text ends. Record the length of each run, from left to right. Spaces count as characters too. For "aa bb",runLengthsis [2, 1, 2]. - Create a list
positiveValuesthat keeps only the numbers inrunLengthsthat are greater than 0, in the same order. - Complete
ribbonRunsPositiveProofStripso it returnspositiveValues. Return it, do not print it.
Example
If line is "rg zci", then runLengths is [1, 1, 2, 1, 1, 1] and ribbonRunsPositiveProofStrip returns [1, 1, 2, 1, 1, 1].
Rules
- Keep repeated numbers.
- If
runLengthsis empty, return [].
Test data
TEST DATA 1: line is "illrx mrrri".
TEST DATA 2: line is "LL lLL".
Examples
Input: line = "illrx mrrri" Output: [1,2,1,1,1,1,3,1]
runLengths is [1, 2, 1, 1, 1, 1, 3, 1]. Keep only numbers greater than 0, without changing their order. Return [1, 2, 1, 1, 1, 1, 3, 1].
Input: line = "LL lLL" Output: [2,1,1,2]
runLengths is [2, 1, 1, 2]. Keep only numbers greater than 0, without changing their order. Return [2, 1, 1, 2].
Input: line = "" Output: []
runLengths is []. Keep only numbers greater than 0, without changing their order. Return [].
Input limits
- 0 <= input size <= 64.
- Answers fit in a signed 32-bit integer: -2,147,483,648 through 2,147,483,647.
- The text uses ASCII characters (a basic character set). Only an ordinary space separates words.
Efficiency goal
Big-O describes how the work or memory needed grows as the input gets larger.
Efficiency goal: time O(n); extra memory, including the helper list, O(n). n is the input length. These labels describe how work and memory grow with the input.
Practice focus
Build runLengths first, then return exactly what the tasks ask for. Follow the order, keep repeated values when the rule says so, and check the empty case.