Merge pull request DaleStudy#611 from jdalma/main

[정현준] 15주차

Author: jdalma

subtree-of-another-tree/jdalma.kt

@@ -0,0 +1,28 @@
+package leetcode_study
+
+import io.kotest.matchers.shouldBe
+import org.junit.jupiter.api.Test
+
+class `subtree-of-another-tree` {
+
+    fun isSubtree(root: TreeNode?, subRoot: TreeNode?): Boolean {
+        if (root == null) return false
+        else if (isSame(root, subRoot)) return true
+
+        return isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot)
+    }
+
+    private fun isSame(root: TreeNode?, subRoot: TreeNode?): Boolean {
+        if (root == null && subRoot == null) return true
+        if (root == null || subRoot == null) return false
+        if (root.`val` != subRoot.`val`) return false
+
+        return isSame(root.left, subRoot.left) && isSame(root.right, subRoot.right)
+    }
+
+    @Test
+    fun `subRoot를 포함한다면 참을 반환한다`() {
+        isSubtree(TreeNode.of(3,4,5,1,2,null,null,null,0), TreeNode.of(4,1,2)) shouldBe false
+        isSubtree(TreeNode.of(3,4,5,1,2,null,null,null), TreeNode.of(4,1,2)) shouldBe true
+    }
+}