Completed day2 for go

2024/go/day1/main.go

@@ -74,6 +74,10 @@ func main() {
 		secondCol = append(secondCol, input[1])
 	}
 
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+
 	answer := Part1(firstCol, secondCol)
 	fmt.Println(answer)
 

2024/go/day2/main.go

@@ -1,10 +1,78 @@
 package main
 
 import (
+	"bufio"
 	"flag"
+	"fmt"
+	"math"
 	"os"
+	"strconv"
+	"strings"
 )
 
+func isSafe(row []int) bool {
+	increasing := true
+	decreasing := true
+	valid := true
+
+	for i := 1; i < len(row); i++ {
+		diff := math.Abs(float64(row[i]) - float64(row[i-1]))
+
+		if diff < 1 || diff > 3 {
+			valid = false
+			break
+		}
+
+		if row[i] < row[i-1] {
+			increasing = false
+		}
+
+		if row[i] > row[i-1] {
+			decreasing = false
+		}
+	}
+
+	if valid && (increasing || decreasing) {
+		return true
+	}
+
+	return false
+}
+
+func Part1(rows [][]int) int {
+	safe := 0
+	for _, row := range rows {
+		if isSafe(row) {
+			safe += 1
+		}
+	}
+
+	return safe
+}
+
+func Part2(rows [][]int) int {
+	safe := 0
+	for _, row := range rows {
+		if isSafe(row) {
+			safe += 1
+			continue
+		}
+
+		for i := 0; i < len(row); i++ {
+			modified := make([]int, len(row)-1)
+			copy(modified[:i], row[:i])
+			copy(modified[i:], row[i+1:])
+
+			if isSafe(modified) {
+				safe += 1
+				break
+			}
+		}
+	}
+
+	return safe
+}
+
 func main() {
 	flag.Parse()
 
@@ -19,4 +87,33 @@ func main() {
 		panic(err)
 	}
 	defer file.Close()
+
+	var rows [][]int
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		var row []int
+
+		for _, num := range strings.Fields(line) {
+			n, err := strconv.Atoi(num)
+			if err != nil {
+				panic(err)
+			}
+
+			row = append(row, n)
+		}
+
+		rows = append(rows, row)
+	}
+
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+
+	answer := Part1(rows)
+	fmt.Println(answer)
+
+	answer = Part2(rows)
+	fmt.Println(answer)
 }

2024/go/test.txt

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9