Fix day3 to consider more complex trees.

vaskoz · Jan 20, 2021 · 886b3d3 · 886b3d3
1 parent ea0fb1f
commit 886b3d3
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Showing 2 changed files with 55 additions and 31 deletions.
diff --git a/day3/problem.go b/day3/problem.go
@@ -30,22 +30,24 @@ func Serialize(root *Node) string {
 	return strings.Join(serialized, " ")
 }
 
-func preorderDeserialize(serialized []string) *Node {
+func preorderDeserialize(serialized []string) (*Node, int) {
 	if len(serialized) == 0 || serialized[0] == "-1" {
-		return nil
+		return nil, 1
 	}
 	v, err := strconv.Atoi(serialized[0])
 	if err != nil {
 		panic("bad serialized data cannot be deserialized")
 	}
 	node := &Node{val: v}
-	node.left = preorderDeserialize(serialized[1:])
-	node.right = preorderDeserialize(serialized[2:])
-	return node
+	advanceLeft, advanceRight := 0, 0
+	node.left, advanceLeft = preorderDeserialize(serialized[1:])
+	node.right, advanceRight = preorderDeserialize(serialized[1+advanceLeft:])
+	return node, 1 + advanceLeft + advanceRight
 }
 
 // Deserialize converts a string into a general binary tree.
 func Deserialize(data string) *Node {
 	serialized := strings.Split(data, " ")
-	return preorderDeserialize(serialized)
+	result, _ := preorderDeserialize(serialized)
+	return result
 }
diff --git a/day3/problem_test.go b/day3/problem_test.go
@@ -1,19 +1,41 @@
 package day3
 
 import (
-	//	"log"
 	"testing"
 )
 
 func TestSerializeAndDeserialize(t *testing.T) {
 	t.Parallel()
-	root := &Node{val: 20,
-		left: nil,
-		right: &Node{val: 8, left: nil,
-			right: &Node{val: 10, left: nil,
-				right: &Node{val: 5}}},
+	root := &Node{
+		val: 20,
+		left: &Node{
+			val: 5,
+			left: &Node{
+				val:  10,
+				left: nil,
+				right: &Node{
+				val:   5,
+					left:  nil,
+					right: nil,
+				},
+			},
+			right: nil,
+		},
+		right: &Node{
+			val:  8,
+			left: nil,
+			right: &Node{
+				val:  10,
+				left: nil,
+				right: &Node{
+					val:   5,
+					left:  nil,
+					right: nil,
+				},
+			},
+		},
 	}
-	expected := "20 -1 8 -1 10 -1 5 -1 -1"
+	expected := "20 5 10 -1 5 -1 -1 -1 8 -1 10 -1 5 -1 -1"
 	var result string
 	if result = Serialize(root); result != expected {
 		t.Errorf("Expected %v but got %v", expected, result)
@@ -49,21 +71,21 @@ func TreeEquality(t1, t2 *Node) bool {
 }
 
 // inorder is a method to debug your inorder traversal of the tree
-//func inorder(n *Node) {
-//if n == nil {
-//return
-//}
-//if n.left != nil {
-//log.Println("going left")
-//} else {
-//log.Println("nothing to the left")
-//}
-//inorder(n.left)
-//log.Println(n.val)
-//if n.right != nil {
-//log.Println("going right")
-//} else {
-//log.Println("nothing to the right")
-//}
-//inorder(n.right)
-//}
+// func inorder(n *Node) {
+// if n == nil {
+// return
+// }
+// if n.left != nil {
+// log.Println("going left")
+// } else {
+// log.Println("nothing to the left")
+// }
+// inorder(n.left)
+// log.Println(n.val)
+// if n.right != nil {
+// log.Println("going right")
+// } else {
+// log.Println("nothing to the right")
+// }
+// inorder(n.right)
+// }