A-M baby

Task/Find-common-directory-path/Go/find-common-directory-path.go

@@ -0,0 +1,77 @@
+package main
+
+import(
+	"fmt"
+	"path"
+	"strings"
+)
+
+func CommonPrefix(sep string, paths ...string) (string) {
+	// Handle special cases.
+	switch len(paths) {
+		case 0:
+			return ""
+		case 1:
+			return path.Clean(paths[0])
+	}
+
+	c := []byte(path.Clean(paths[0]))
+
+	// Ignore the first path since it's already in c.
+	for _, v := range(paths[1:]) {
+		// Clean up each path before testing it.
+		v = path.Clean(v)
+
+		// Get the length of the shorter slice.
+		shorter := len(v)
+		if len(v) > len(c) {
+			shorter = len(c)
+		}
+
+		// Find the first non-common character and copy up to it into c.
+		for i := 0; i < shorter; i++ {
+			if v[i] != c[i] {
+				c = c[0:i]
+				break
+			}
+		}
+	}
+
+	// Correct for problem caused by prepending the actual common path to the
+	// list of paths searched through.
+	for _, v := range(paths) {
+		if len(v) > len(c) {
+			if strings.HasPrefix(v, string(c)) {
+				if len(v) > len(c) + len(sep) {
+					if v[len(c):len(c)+len(sep)] == sep {
+						c = append(c, []byte(sep)...)
+						break
+					}
+				}
+			}
+		}
+	}
+
+	// Remove trailing non-seperator characters.
+	for i := len(c)-1; i >= 0; i-- {
+		if i + len(sep) > len(c) {
+			continue
+		}
+
+		if string(c[i:i+len(sep)]) == sep {
+			c = c[0:i]
+			break
+		}
+	}
+
+	return string(c)
+}
+
+func main() {
+	c := CommonPrefix("/",
+		"/home/user1/tmp/coverage/test",
+		"/home/user1/tmp/covert/operator",
+		"/home/user1/tmp/coven/members",
+	)
+	fmt.Printf("%v\n", c)
+}