Added the first days

2021/05/first.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+
+	"git.adyxax.org/aoc/2021/05/line"
+)
+
+func main() {
+	matrix := make([][]int, 1000)
+	for i := 0; i < 1000; i++ {
+		matrix[i] = make([]int, 1000)
+	}
+
+	parser := line.NewParser(bufio.NewReader(os.Stdin))
+	for {
+		l, err := parser.Parse()
+		if err != nil {
+			break
+		}
+		if l.X1 == l.X2 {
+			if l.Y1 > l.Y2 {
+				l.Y1, l.Y2 = l.Y2, l.Y1
+			}
+			for i := l.Y1; i <= l.Y2; i++ {
+				matrix[l.X1][i]++
+			}
+		} else if l.Y1 == l.Y2 {
+			if l.X1 > l.X2 {
+				l.X1, l.X2 = l.X2, l.X1
+			}
+			for i := l.X1; i <= l.X2; i++ {
+				matrix[i][l.Y1]++
+			}
+		}
+	}
+	score := 0
+	for i := 0; i < 1000; i++ {
+		for j := 0; j < 1000; j++ {
+			if matrix[i][j] >= 2 {
+				score++
+			}
+		}
+	}
+	fmt.Println(score)
+}