/
day10.go
96 lines (76 loc) · 2 KB
/
day10.go
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package hbery_aoc2015
import (
"errors"
"fmt"
"strconv"
"strings"
)
// too slow..
func look_and_say_strings(input string) (string, error) {
var new_string string
var currnum string = ""
var numcount int = 0
for _, num := range strings.Split(input, "") {
if num == currnum {
numcount++
} else {
if currnum == "" {
currnum = num
numcount++
continue
}
new_string = fmt.Sprintf("%s%d%s", new_string, numcount, currnum)
currnum = num
numcount = 1
}
}
// last num scenario
new_string = fmt.Sprintf("%s%d%s", new_string, numcount, currnum)
return new_string, nil
}
func look_and_say_bytes(input []byte) ([]byte, error) {
var new_numbers []byte
for i := 0; i < len(input); i++ {
start_idx := i
for i < len(input)-1 && input[i+1] == input[i] {
i++
}
end_idx := i
numcount := end_idx - start_idx + 1
new_numbers = append(new_numbers, strconv.Itoa(numcount)[0], input[i])
}
return new_numbers, nil
}
func day10_p1(input string) (int64, error) {
var result []byte
var repetition int = 40
var err error
result = []byte(strings.TrimSuffix(input, "\n"))
for i := 0; i < repetition; i++ {
if result, err = look_and_say_bytes(result); err != nil {
return -1, errors.New(fmt.Sprintf("Error: new creation failed at rep %d at input string: %s", i, result))
}
}
return int64(len(result)), nil
}
func day10_p2(input string) (int64, error) {
var result []byte
var repetition int = 50
var err error
result = []byte(strings.TrimSuffix(input, "\n"))
for i := 0; i < repetition; i++ {
if result, err = look_and_say_bytes(result); err != nil {
return -1, errors.New(fmt.Sprintf("Error: new creation failed at rep %d at input string: %s", i, result))
}
}
return int64(len(result)), nil
}
func Solution_Day10(part int, input string) (int64, error) {
if part == 1 {
return day10_p1(input)
} else if part == 2 {
return day10_p2(input)
} else {
return 0, errors.New(fmt.Sprintf("Error: Hold on cowboy. No such part (%d) of this day task", part))
}
}