Leetcode 572 Subtree of Another Tree

Author: jiajionline

0572_Subtree of Another Tree/SubtreeofAnotherTree.java

@@ -1,15 +1,12 @@
 class Solution {
- public boolean isSubtree(TreeNode s, TreeNode t) {
- if(s == null) return false;
- return isSameTree(s, t) || isSubtree(s.left, t) || isSubtree(s.right, t);
+ public boolean isSubtree(TreeNode root, TreeNode subRoot) {
+ if(root == null) return false;
+ return isSameTree(root, subRoot) || isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot);
  }
 
- private boolean isSameTree(TreeNode s, TreeNode t){
- if(s == null && t == null) return true;
- if(s!=null && t!=null && s.val == t.val){
- return isSameTree(s.left, t.left) && isSameTree(s.right, t.right);
- }else{
- return false;
- }
+ private boolean isSameTree(TreeNode nodeA, TreeNode nodeB) {
+ if(nodeA == null && nodeB == null) return true;
+ if(nodeA == null || nodeB == null || nodeA.val != nodeB.val) return false;
+ return isSameTree(nodeA.left, nodeB.left) && isSameTree(nodeA.right, nodeB.right);
  }
 }