144 lines
2.1 KiB
Go
144 lines
2.1 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bufio"
|
||
|
|
"fmt"
|
||
|
|
"os"
|
||
|
|
"strconv"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
const MaxInt = int((^uint(0) >> 1))
|
||
|
|
|
||
|
|
type Range struct {
|
||
|
|
dst int
|
||
|
|
src int
|
||
|
|
len int
|
||
|
|
}
|
||
|
|
|
||
|
|
func (r Range) Map(n int) (int, bool) {
|
||
|
|
if n < r.src || n > (r.src+r.len-1) {
|
||
|
|
return 0, false
|
||
|
|
}
|
||
|
|
return r.dst - r.src + n, true
|
||
|
|
}
|
||
|
|
|
||
|
|
type Map struct {
|
||
|
|
name string
|
||
|
|
ranges []Range
|
||
|
|
}
|
||
|
|
|
||
|
|
func (m *Map) Append(r Range) {
|
||
|
|
m.ranges = append(m.ranges, r)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (m *Map) Map(n int) int {
|
||
|
|
for i := range m.ranges {
|
||
|
|
x, ok := m.ranges[i].Map(n)
|
||
|
|
if ok {
|
||
|
|
return x
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return n
|
||
|
|
}
|
||
|
|
|
||
|
|
type Almanac struct {
|
||
|
|
seeds []int
|
||
|
|
maps []*Map
|
||
|
|
}
|
||
|
|
|
||
|
|
func (a *Almanac) ParseFile(name string) error {
|
||
|
|
f, err := os.Open(name)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
defer f.Close()
|
||
|
|
scanner := bufio.NewScanner(f)
|
||
|
|
scanner.Scan()
|
||
|
|
seedsStr := scanner.Text()
|
||
|
|
seeds := strToInts(seedsStr[7:])
|
||
|
|
a.seeds = seeds
|
||
|
|
scanner.Scan()
|
||
|
|
var m *Map
|
||
|
|
for scanner.Scan() {
|
||
|
|
s := scanner.Text()
|
||
|
|
s = strings.Trim(s, " \n")
|
||
|
|
if s == "" {
|
||
|
|
a.maps = append(a.maps, m)
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
if s[0] > '9' {
|
||
|
|
m = &Map{
|
||
|
|
name: s,
|
||
|
|
ranges: []Range{},
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
nums := strToInts(s)
|
||
|
|
r := Range{
|
||
|
|
dst: nums[0],
|
||
|
|
src: nums[1],
|
||
|
|
len: nums[2],
|
||
|
|
}
|
||
|
|
m.Append(r)
|
||
|
|
}
|
||
|
|
a.maps = append(a.maps, m)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (a *Almanac) seedToLoc(n int) int {
|
||
|
|
for i := range a.maps {
|
||
|
|
n = a.maps[i].Map(n)
|
||
|
|
}
|
||
|
|
return n
|
||
|
|
}
|
||
|
|
|
||
|
|
func (a *Almanac) ClosestForSeeds() int {
|
||
|
|
result := MaxInt
|
||
|
|
for _, n := range a.seeds {
|
||
|
|
loc := a.seedToLoc(n)
|
||
|
|
if loc < result {
|
||
|
|
result = loc
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return result
|
||
|
|
}
|
||
|
|
|
||
|
|
func (a *Almanac) ClosestForRanges() int {
|
||
|
|
result := MaxInt
|
||
|
|
for i := 0; i < (len(a.seeds) - 2); i += 2 {
|
||
|
|
for j := a.seeds[i]; j < (a.seeds[i] + a.seeds[i+1]); j++ {
|
||
|
|
loc := a.seedToLoc(j)
|
||
|
|
if loc < result {
|
||
|
|
result = loc
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return result
|
||
|
|
}
|
||
|
|
|
||
|
|
func strToInts(s string) []int {
|
||
|
|
s = strings.Trim(s, " \n")
|
||
|
|
split := strings.Split(s, " ")
|
||
|
|
nums := []int{}
|
||
|
|
for _, x := range split {
|
||
|
|
n, err := strconv.Atoi(x)
|
||
|
|
if err != nil {
|
||
|
|
panic(err)
|
||
|
|
}
|
||
|
|
nums = append(nums, n)
|
||
|
|
}
|
||
|
|
return nums
|
||
|
|
}
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
a := new(Almanac)
|
||
|
|
a.ParseFile("input.txt")
|
||
|
|
|
||
|
|
x := a.ClosestForSeeds()
|
||
|
|
fmt.Println(x)
|
||
|
|
|
||
|
|
y := a.ClosestForRanges()
|
||
|
|
fmt.Println(y)
|
||
|
|
}
|