Merge pull request #636 from openset/develop

Add: Alphabet Board Path

Author: Shuo

problems/alphabet-board-path/alphabet_board_path.go

@@ -0,0 +1,42 @@
+package alphabet_board_path
+
+import "strings"
+
+func alphabetBoardPath(target string) string {
+	var sb strings.Builder
+	// form [x1,y1] move to [x2,y2]
+	move := func(x1, y1, x2, y2 int) {
+		for y1 > y2 {
+			y1--
+			sb.WriteByte('L')
+		}
+		for x1 > x2 {
+			x1--
+			sb.WriteByte('U')
+		}
+		for x1 < x2 {
+			x1++
+			sb.WriteByte('D')
+		}
+		for y1 < y2 {
+			y1++
+			sb.WriteByte('R')
+		}
+		return
+	}
+
+	x1, y1 := 0, 0
+	for _, r := range target {
+		x2, y2 := coordinate(r)
+		move(x1, y1, x2, y2)
+		sb.WriteByte('!')
+		x1, y1 = x2, y2
+	}
+	return sb.String()
+}
+
+func coordinate(r rune) (x, y int) {
+	a := int(r - 'a')
+	x, y = a/5, a%5
+	return
+}