Omid - Challenge 205

data-challenges
advanced-exercises
🔰 Result Question ID OFDMSD MPMXM/FS PPM/PM/ MPMXM6FS PPM4PM7
Published

March 24, 2026

Illustration for Omid - Challenge 205

Challenge Description

🔰 Result Question ID OFDMSD MPMXM/FS PPM/PM/ MPMXM6FS PPM4PM7

Solutions

library(tidyverse)
library(readxl)

path = "files/CH-205 Missing Char.xlsx"
input = read_excel(path, range = "B2:B7")
test  = read_excel(path, range = "D2:D7")

result = input %>%
  mutate(w_index = row_number()) %>%
  separate_rows(ID, sep = "") %>%
  filter(ID != "") %>%
  mutate(l_index = row_number(), .by = w_index) %>%
  mutate(ID = ifelse(ID == '/', l_index, ID)) %>%
  summarise(ID = paste(ID, collapse = ""), .by = w_index) %>%
  select(-w_index)

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Aggregates or ranks values at the relevant grouping level

    • Builds the intermediate columns that drive the final result

  • 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 = "CH-205 Missing Char.xlsx"
input = pd.read_excel(path, usecols="B", skiprows=1, nrows=6)
test = pd.read_excel(path, usecols="D", skiprows=1, nrows=6)

def replace_slashes_with_indices(word):
    return ''.join(str(i + 1) if char == '/' else char for i, char in enumerate(word))

input['Modified'] = input.iloc[:, 0].apply(replace_slashes_with_indices)

  • 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.