Unoptimised day 8

08/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"github.com/csmith/aoc-2019/common"
+	"math"
+)
+
+const width = 25
+const height = 6
+
+func checkChecksum(layer string, fewestZeros *int, checksum *int) {
+	counts := []int{0, 0, 0}
+	for _, r := range layer {
+		counts[r-'0']++
+	}
+
+	if counts[0] < *fewestZeros {
+		*fewestZeros = counts[0]
+		*checksum = counts[1] * counts[2]
+	}
+}
+
+func main() {
+	var (
+		input       = common.ReadFileAsStrings("08/input.txt")[0]
+		fewestZeros = math.MaxInt64
+		checksum    = 0
+		pixels      [width * height]rune
+	)
+
+	for i := len(input) - width*height; i >= 0; i -= width * height {
+		layer := input[i : i+width*height]
+		checkChecksum(layer, &fewestZeros, &checksum)
+		for i, r := range layer {
+			if r == '0' {
+				pixels[i] = ' '
+			} else if r == '1' {
+				pixels[i] = '█'
+			}
+		}
+	}
+
+	fmt.Printf("%d\n", checksum)
+	for i, p := range pixels {
+		fmt.Printf("%c", p)
+		if i%width == width-1 {
+			fmt.Printf("\n")
+		}
+	}
+}