advent-of-code/2023/day-1/part_two.go
Dan Anglin ec8824682d
refactor(Day 1): replace recursive calls with loop
For Part 2, the recursive function calls are replaced with a for loop in
the form of a while loop.
2023-12-04 23:07:45 +00:00

83 lines
1.8 KiB
Go

package main
import (
"strings"
)
const (
one = "one"
two = "two"
three = "three"
four = "four"
five = "five"
six = "six"
seven = "seven"
eight = "eight"
nine = "nine"
)
func partTwoCalculateSumCalibrationValues(document []string) int {
sum := 0
for _, line := range document {
sum = sum + partTwoCalibrationValue(line)
}
return sum
}
func partTwoCalibrationValue(line string) int {
var digits []int
for len(line) > 0 {
switch {
case (line[0] >= '0') && (line[0] <= '9'):
digits = append(digits, int(line[0]-'0'))
line = line[1:]
case strings.HasPrefix(line, one):
digits = append(digits, 1)
trimLength := len(one) - 1
line = line[trimLength:]
case strings.HasPrefix(line, two):
digits = append(digits, 2)
trimLength := len(two) - 1
line = line[trimLength:]
case strings.HasPrefix(line, three):
digits = append(digits, 3)
trimLength := len(three) - 1
line = line[trimLength:]
case strings.HasPrefix(line, four):
digits = append(digits, 4)
trimLength := len(four) - 1
line = line[trimLength:]
case strings.HasPrefix(line, five):
digits = append(digits, 5)
trimLength := len(five) - 1
line = line[trimLength:]
case strings.HasPrefix(line, six):
digits = append(digits, 6)
trimLength := len(six) - 1
line = line[trimLength:]
case strings.HasPrefix(line, seven):
digits = append(digits, 7)
trimLength := len(seven) - 1
line = line[trimLength:]
case strings.HasPrefix(line, eight):
digits = append(digits, 8)
trimLength := len(eight) - 1
line = line[trimLength:]
case strings.HasPrefix(line, nine):
digits = append(digits, 9)
trimLength := len(nine) - 1
line = line[trimLength:]
default:
line = line[1:]
}
}
if len(digits) == 0 {
return 0
}
return (10*digits[0] + digits[len(digits)-1])
}