leetcode-101. 对称二叉树

用go写代码现在还算是比较快了

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func isSymmetric(root *TreeNode) bool {
    if root == nil {
        return true
    }
 
    return dfs(root.Left, root.Right)
}
 
func dfs(left *TreeNode, right *TreeNode) bool {
    if left == nil && right == nil {
        return true
    }
 
    if left == nil || right == nil {
        return false
    }
 
    if left.Val != right.Val {
        return false
    }
 
    return dfs(left.Left, right.Right) && dfs(left.Right, right.Left)
}

参考

101. 对称二叉树 - 力扣（Leetcode）