Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
给定两颗二叉树,判断这两颗树是否相同,它们相同的条件是结构相同,对应节点的值也必须相同。同样采用递归的方式,先比较对应点的节点是否为空,如果都为空,那么在当前状态下返回true;如果一个空,一个不为空,返回false。如果都不为空的情况下,判断对应点的值,如果值不同返回false;如果值相同,递归判断当前节点的子树。代码如下:
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if(p == null && q == null) { return true; } else if(p != null && q != null) { if(p.val != q.val) return false; return isSameTree(p.left, q.left) && isSameTree(p.right, q.right); } return false; } }