Omid - Challenge 333

data-challenges
advanced-exercises
🔰 Question Table Result Table Column 1 Column 2 A X C B
Published

March 24, 2026

Illustration for Omid - Challenge 333

Challenge Description

🔰 Question Table Result Table Column 1 Column 2 A X C B

Solutions

library(tidyverse)
library(readxl)

path <- "300-399/333/CH-333 Pattern Combinations.xlsx"
input <- read_excel(path, range = "B2:D8")
test <- read_excel(path, range = "F2:F8")

roll_column <- function(column, steps) {
  n <- length(column)
  c(tail(column, n - steps %% n), head(column, steps %% n))
}

result = input %>%
  mutate(
    `Column 1` = `Column 1`,
    `Column 2` = roll_column(`Column 2`, 1),
    `Column 3` = roll_column(`Column 3`, 2)
  ) %>%
  unite("Combinations", `Column 1`:`Column 3`, sep = "")

all.equal(result, test)
# [1] TRUE

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • 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
import numpy as np

path = "300-399/333/CH-333 Pattern Combinations.xlsx"
input = pd.read_excel(path, usecols="B:D", skiprows=1, nrows=7)
test = pd.read_excel(path, usecols="F", skiprows=1, nrows=7)

def shift_column(s, n):
    return np.roll(s.to_numpy(), -n)

input['Column 2'] = shift_column(input['Column 2'], 1)
input['Column 3'] = shift_column(input['Column 3'], 2)
input['Combinations'] = input.astype(str).agg(''.join, axis=1)

print(input['Combinations'].equals(test['Combinations'])) # True

  • Logic:

    • Reads the workbook ranges needed for the challenge

  • 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.