Excel BI - Excel Challenge 677

excel-challenges

excel-formulas

🔰 Generate the given pattern.

Published

March 24, 2026

Illustration for Excel BI - Excel Challenge 677

Challenge Description

🔰 Generate the given pattern.

Solutions

library(tidyverse)
library(readxl)

path = "Excel/677 Generate the Pattern.xlsx"
test  = read_excel(path, range = "B2:R10", col_names = FALSE) %>% as.matrix() %>% replace(is.na(.), "")

M = matrix("", 9, 17)

generate_sequence <- function(X) {
  if (X == 1) return(1)
  c(seq(X, 1, by = -1), seq(2, X, by = 1))
}

for (i in 1:9) {
  seq_i <- generate_sequence(i)
  M[i, 1:length(seq_i)] <- seq_i
}

all.equal(M, test, check.attributes = FALSE)
#> [1] TRUE

Logic: Read the workbook ranges needed for the challenge; Iterate through the sequence until the rule is satisfied.
Strengths: The algorithm is explicit about the sequence rule, so the control flow is easy to validate against the prompt.
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 non-obvious part is the local rule inside the loop, because that rule determines the whole output.

import numpy as np
import pandas as pd

path = "677 Generate the Pattern.xlsx"
test = pd.read_excel(path, sheet_name=0, usecols="B:R", skiprows=1, nrows=9, header=None).fillna("").to_numpy()

M = np.full((9, 17), "", dtype=object)
def generate_sequence(X):
    return [x for x in range(X, 0, -1)] + [x for x in range(2, X + 1)]
M = np.array([generate_sequence(i) + [""] * (17 - len(generate_sequence(i))) for i in range(1, 10)], dtype=object)

print(np.array_equal(M, test))

The Python version keeps the algorithm explicit, which helps when the challenge depends on a greedy or iterative rule.

Difficulty Level

Easy / Medium

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