2022/go/day05/day05.go

   1 package day05
   2
   3 import (
   4         "fmt"
   5         "strings"
   6
   7         "github.com/philhanna/stack"
   8 )
   9
  10 func Part1(input string) (result string) {
  11
  12         result = ""
  13         var stacks [9]stack.Stack[string]
  14         var lineNo int
  15
  16         for i := 0; i < 9; i++ {
  17                 stacks[i] = stack.NewStack[string]()
  18         }
  19
  20         lines := strings.Split(input, "\n")
  21         for n, line := range lines {
  22                 if line == " 1   2   3   4   5   6   7   8   9 " {
  23                         lineNo = n + 2
  24                         break
  25                 }
  26                 for i, r := range line {
  27                         if r != ' ' && r != '[' && r != ']' {
  28                                 stacks[i/4].Push(string(r))
  29                         }
  30                 }
  31         }
  32         for i := 0; i < 9; i++ {
  33                 stacks[i].Reverse()
  34         }
  35         var quantity, from, to int
  36         for _, line := range lines[lineNo:] {
  37                 fmt.Sscanf(line, "move %d from %d to %d", &quantity, &from, &to)
  38                 for i := 0; i < quantity; i++ {
  39                         value, _ := (stacks[from-1]).Pop()
  40                         stacks[to-1].Push(value)
  41                 }
  42         }
  43         for i := 0; i < 9; i++ {
  44                 item, _ := stacks[i].Peek()
  45                 result = result + item
  46         }
  47         return
  48 }
  49
  50 func Part2(input string) (result string) {
  51
  52         result = ""
  53         var stacks [9]stack.Stack[string]
  54         tmp := stack.NewStack[string]()
  55         var lineNo int
  56
  57         for i := 0; i < 9; i++ {
  58                 stacks[i] = stack.NewStack[string]()
  59         }
  60
  61         lines := strings.Split(input, "\n")
  62         for n, line := range lines {
  63                 if line == " 1   2   3   4   5   6   7   8   9 " {
  64                         lineNo = n + 2
  65                         break
  66                 }
  67                 for i, r := range line {
  68                         if r != ' ' && r != '[' && r != ']' {
  69                                 stacks[i/4].Push(string(r))
  70                         }
  71                 }
  72         }
  73         for i := 0; i < 9; i++ {
  74                 stacks[i].Reverse()
  75         }
  76         var quantity, from, to int
  77         for _, line := range lines[lineNo:] {
  78                 fmt.Sscanf(line, "move %d from %d to %d", &quantity, &from, &to)
  79                 for i := 0; i < quantity; i++ {
  80                         value, _ := (stacks[from-1]).Pop()
  81                         tmp.Push(value)
  82                 }
  83                 for i := 0; i < quantity; i++ {
  84                         value, _ := tmp.Pop()
  85                         stacks[to-1].Push(value)
  86                 }
  87         }
  88         for i := 0; i < 9; i++ {
  89                 item, _ := stacks[i].Peek()
  90                 result = result + item
  91         }
  92         return
  93 }