🌅

solutions/day8/day8.go

@@ -0,0 +1,142 @@
+package day8
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func isVisible(treeMap [][]int, x int, y int) bool {
+	treeHeight := treeMap[y][x]
+
+	left_test := true
+	for trial := 0; trial < x; trial++ {
+		left_test = left_test && treeMap[y][trial] < treeHeight
+	}
+
+	right_test := true
+	for trial := x + 1; trial < len(treeMap[y]); trial++ {
+		right_test = right_test && treeMap[y][trial] < treeHeight
+	}
+
+	up_test := true
+	for trial := 0; trial < y; trial++ {
+		up_test = up_test && treeMap[trial][x] < treeHeight
+	}
+
+	down_test := true
+	for trial := y + 1; trial < len(treeMap); trial++ {
+		down_test = down_test && treeMap[trial][x] < treeHeight
+	}
+	fmt.Println("Test for x", x, "y", y, "which has height", treeHeight, "tests are", left_test, right_test, up_test, down_test)
+
+	return (left_test || right_test || up_test || down_test)
+}
+
+func score(treeMap [][]int, x int, y int) int {
+	treeHeight := treeMap[y][x]
+
+	if x == 0 || y == 0 {
+		return 0
+	}
+
+	final := 1
+
+	score := 0
+	for trial := x - 1; trial >= 0; trial-- {
+		if treeMap[y][trial] >= treeHeight {
+			score += 1
+			break
+		}
+		score += 1
+	}
+	final *= score
+
+	score = 0
+	for trial := x + 1; trial < len(treeMap[y]); trial++ {
+		if treeMap[y][trial] >= treeHeight {
+			score += 1
+			break
+		}
+		score += 1
+	}
+	final *= score
+
+	score = 0
+	for trial := y - 1; trial >= 0; trial-- {
+		if treeMap[trial][x] >= treeHeight {
+			score += 1
+			break
+		}
+		score += 1
+	}
+	final *= score
+
+	score = 0
+	for trial := y + 1; trial < len(treeMap); trial++ {
+		if treeMap[trial][x] >= treeHeight {
+			score += 1
+			break
+		}
+		score += 1
+	}
+	final *= score
+
+	return final
+}
+
+func Run(filename string) {
+	file, err := os.Open(filename)
+	if err != nil {
+		fmt.Println("Error opening file:", err)
+		return
+	}
+
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+
+	treeMap := [][]int{}
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		row := []int{}
+		for _, c := range line {
+			value, err := strconv.Atoi(string(c))
+			if err != nil {
+				fmt.Println("PANIC: bad character")
+				return
+			}
+			row = append(row, value)
+		}
+		treeMap = append(treeMap, row)
+	}
+
+	file.Close()
+
+	width := len(treeMap[0])
+	height := len(treeMap)
+
+	visibleTrees := 2*width + 2*height - 4
+	bestScore := 1
+
+	for y := 1; y < (height - 1); y++ {
+		for x := 1; x < (width - 1); x++ {
+			if isVisible(treeMap, x, y) {
+				visibleTrees += 1
+				//fmt.Printf("*")
+			} else {
+				//fmt.Printf("%d", treeMap[y][x])
+			}
+
+			current := score(treeMap, x, y)
+			if current > bestScore {
+				bestScore = current
+			}
+		}
+		//fmt.Println()
+	}
+
+	fmt.Println("There are", visibleTrees, "visible trees")
+	fmt.Println("Best score is", bestScore)
+}