day9,10,11

2023-12-13 23:54:55 +00:00
parent 84e8207917
commit 3948cbaa8c
11 changed files with 1115 additions and 2 deletions
--- a/2023/go/day11/day11.go
+++ b/2023/go/day11/day11.go
@@ -0,0 +1,146 @@
+package day11
+
+import (
+	"adventofcode2023/utils"
+	_ "fmt"
+	"strings"
+)
+
+type Galaxy struct {
+	x int
+	y int
+}
+
+func Part1(input string) int {
+	galaxies := []Galaxy{}
+	lines := strings.Split(input, "\n")
+	var expand_rows []int
+	var expand_cols []int
+	for y,line := range lines {
+		for x,char := range line {
+			if char == '#' {
+				galaxies = append(galaxies, Galaxy{x, y})
+			}
+		}
+	}
+	// fmt.Println(galaxies)
+	for y,line := range lines {
+		no_galaxy := true
+		for _,char := range line {
+			if char != '.' {
+				no_galaxy = false
+				break
+			}
+		}
+		if no_galaxy {
+			expand_rows = append(expand_rows, y)
+		}
+	}
+	for x:=0;x<len(lines[0]);x++ {
+		no_galaxy := true
+		for _,line := range lines {
+				if line[x] != '.' {
+					no_galaxy = false
+					break
+				}
+		}
+		if no_galaxy {
+			expand_cols = append(expand_cols, x)
+		}
+	}
+	galaxies = expand_row(expand_rows, galaxies, true)
+	galaxies = expand_col(expand_cols, galaxies, true)
+//	fmt.Printf("r: %v c: %v\n%v\n", expand_rows, expand_cols, galaxies)
+	dist := 0
+	for i:=0;i<len(galaxies)-1;i++{
+		g1 := galaxies[i]
+		for _, g2 := range galaxies[i+1:] {
+			dist = dist + distance(g1, g2)
+		}
+	}
+	return dist
+}
+
+func Part2(input string) int {
+	galaxies := []Galaxy{}
+	lines := strings.Split(input, "\n")
+	var expand_rows []int
+	var expand_cols []int
+	for y,line := range lines {
+		for x,char := range line {
+			if char == '#' {
+				galaxies = append(galaxies, Galaxy{x, y})
+			}
+		}
+	}
+//	fmt.Println(galaxies)
+	for y,line := range lines {
+		no_galaxy := true
+		for _,char := range line {
+			if char != '.' {
+				no_galaxy = false
+				break
+			}
+		}
+		if no_galaxy {
+			expand_rows = append(expand_rows, y)
+		}
+	}
+	for x:=0;x<len(lines[0]);x++ {
+		no_galaxy := true
+		for _,line := range lines {
+				if line[x] != '.' {
+					no_galaxy = false
+					break
+				}
+		}
+		if no_galaxy {
+			expand_cols = append(expand_cols, x)
+		}
+	}
+	galaxies = expand_row(expand_rows, galaxies, false)
+	galaxies = expand_col(expand_cols, galaxies, false)
+//	fmt.Printf("r: %v c: %v\n%v\n", expand_rows, expand_cols, galaxies)
+	dist := 0
+	for i:=0;i<len(galaxies)-1;i++{
+		g1 := galaxies[i]
+		for _, g2 := range galaxies[i+1:] {
+			dist = dist + distance(g1, g2)
+		}
+	}
+	return dist
+}
+
+func expand_row(rows []int, galaxies []Galaxy, partOne bool) []Galaxy {
+	new := []Galaxy{}
+	for _,galaxy := range galaxies {
+		new = append(new, Galaxy{galaxy.x, galaxy.y + howMany(rows, galaxy.y, partOne)})
+	}
+	return new
+}
+
+func expand_col(cols []int, galaxies []Galaxy, partOne bool) []Galaxy {
+	new := []Galaxy{}
+	for _,galaxy := range galaxies {
+		new = append(new, Galaxy{galaxy.x  + howMany(cols, galaxy.x, partOne), galaxy.y})
+	}
+	return new
+}
+
+func howMany(xs []int, a int, partOne bool) int {
+	count := 0
+	incr := 1
+	if !partOne { incr = 1000000 - 1 }
+	for _,x := range xs {
+		if x < a {
+			count = count + incr
+		}
+	}
+	return count
+}
+
+func distance(g1 Galaxy, g2 Galaxy) int {
+	val := utils.Abs(g1.x - g2.x) + utils.Abs(g1.y - g2.y)
+//	fmt.Printf("%v - %v = %v\n", g1, g2, val)
+	return val
+}