Omid - Challenge 315

data-challenges
advanced-exercises
🔰 Identify and extract all subsequences of 3 or more consecutive numbers.
Published

March 24, 2026

Illustration for Omid - Challenge 315

Challenge Description

🔰 Identify and extract all subsequences of 3 or more consecutive numbers.

Solutions

library(tidyverse)
library(readxl)

path = "files/300-399/315/CH-315 Consecutive numbers.xlsx"
input = read_excel(path, range = "B1:B14")
test  = read_excel(path, range = "E1:E4")

result = as_tibble(embed(input$Question, 3)[,3:1]) %>%
  filter(V2 - V1 == 1, V3 - V2 == 1) %>%
  unite("Result", V1:V3, sep = ".")

print(result)

  • Logic:

    • Reads the workbook ranges needed for the challenge

  • Strengths:

    • The R solution stays close to the workbook rule and keeps the transformation compact.

  • Areas for Improvement:

    • The code assumes the sheet structure and source ranges remain stable.

  • Gem:

    • The strongest part of the solution is choosing the right intermediate representation before shaping the final output.
import pandas as pd

path = "300-399/315/CH-315 Consecutive numbers.xlsx"
numbers = pd.read_excel(path, usecols="B", nrows=14).iloc[:, 0].values

result = pd.DataFrame(
    [(a, b, c) for a, b, c in zip(numbers, numbers[1:], numbers[2:]) if c - a == 2],
    columns=['V1', 'V2', 'V3']
)
result['Result'] = result.apply(lambda r: f"{r.V1}.{r.V2}.{r.V3}", axis=1)

print(result[['Result']])

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Applies the rule iteratively until the output stabilizes

  • Strengths:

    • The Python version follows the same rule in a direct dataframe-oriented implementation.

  • Areas for Improvement:

    • The code assumes the workbook layout remains stable, so any sheet redesign would require small adjustments.

  • Gem:

    • The implementation stays close to the original workbook rule instead of adding unnecessary abstraction.

Difficulty Level

This task is moderate:

  • The business rule is readable, but the workbook still requires careful implementation to reach the expected layout.