package main import ( "bufio" "fmt" "os" "git.adyxax.org/aoc/2021/05/line" ) func abs(a int) int { if a < 0 { return -a } return a } func computeDelta(a, b int) int { if a < b { return 1 } else if a > b { return -1 } return 0 } 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 } length := abs(l.X2 - l.X1) if length == 0 { length = abs(l.Y2 - l.Y1) } dx := computeDelta(l.X1, l.X2) dy := computeDelta(l.Y1, l.Y2) for i := 0; i <= length; i++ { matrix[l.X1+i*dx][l.Y1+i*dy]++ } } score := 0 for i := 0; i < 1000; i++ { for j := 0; j < 1000; j++ { if matrix[i][j] >= 2 { score++ } } } fmt.Println(score) }