Check if two binary trees are identical. Identical means the two binary trees have the same structure and every identical position has the same value.
Example
1 1
/ \ / \
2 2 and 2 2
/ /
4 4
are identical.
1 1
/ \ / \
2 3 and 2 3
/ \
4 4
are not identical.
/**
* Definition of TreeNode:
* public class TreeNode {
* public int val;
* public TreeNode left, right;
* public TreeNode(int val) {
* this.val = val;
* this.left = this.right = null;
* }
* }
*/
public class Solution {
/**
* @param a, b, the root of binary trees.
* @return true if they are identical, or false.
*/
public boolean isIdentical(TreeNode a, TreeNode b) {
if (a == null && b == null) return true;
if (a == null || b == null) return false; if (a.val != b.val) return false; return isIdentical(a.left, b.left) && isIdentical(a.right, b.right);
}
}