Your calculation isn’t quite right. It looks like some digits are actually spelled out with letters: one, two, three, four, five, six, seven, eight, and nine also count as valid “digits”.

Equipped with this new information, you now need to find the real first and last digit on each line.

Assignment

Write a bash shell script trebuchet that takes the pathname of a calibration document as its argument. The shell script must output the sum of all calibration values to stdout. For example, if we take this calibration document (data.txt¹)

two1nine
eightwothree
abcone2threexyz
xtwone3four
4nineeightseven2
zoneight234
7pqrstsixteen

the calibration values are 29, 83, 13, 24, 42, 14, and 76. Adding these together produces 281.

Example

In this interactive session, we assume that the text file data.txt² is in the current directory.

$ trebuchet data.txt
281

Advent of Code 2023

This assignment is based on Eric Wastl’s Advent of Code 2023³.