Excel BI - Excel Challenge 650

excel-challenges
excel-formulas
🔰 List the bottom 3 unique values across the columns.
Published

March 24, 2026

Illustration for Excel BI - Excel Challenge 650

Challenge Description

🔰 List the bottom 3 unique values across the columns.

Solutions

library(tidyverse)
library(readxl)

path = "Excel/650 Top 3 Across Columns.xlsx"
input = read_excel(path, range = "A1:E15")
test  = read_excel(path, range = "G1:G6") %>% pull()

result = input %>%
  summarise(across(everything(), ~ paste(sort(unique(na.omit(.)))[1:3], collapse = ", "))) %>%
  as.list() %>%
  unlist()

all.equal(result, test)
# [1] TRUE
  • Logic: Read the workbook ranges needed for the challenge; Aggregate or rank the data at the required grouping level.
  • Strengths: The code maps the workbook rule into a compact, reproducible pipeline.
  • Areas for Improvement: The solution assumes the workbook layout and selected ranges remain stable, so any structural change in the sheet would require small adjustments.
  • Gem: The elegant part is how little code is needed once the correct intermediate representation is chosen.
import pandas as pd
path = "650 Top 3 Across Columns.xlsx"
input = pd.read_excel(path, usecols="A:E", nrows=15)
test = pd.read_excel(path, usecols="G", nrows=5).values.flatten().tolist()

result = input.apply(lambda col: ', '.join(map(str, sorted(col.dropna().astype(int).unique())[:3]))).tolist()

print(result == test) # True

The Python version mirrors the same workbook logic with a concise, direct implementation.

Difficulty Level

Easy / Medium

The business rule is clear, though the workbook still needs a few transformation steps to reach the expected output.