题解 | #对称的二叉树#
对称的二叉树
https://www.nowcoder.com/practice/ff05d44dfdb04e1d83bdbdab320efbcb
/*class TreeNode {
* val: number
* left: TreeNode | null
* right: TreeNode | null
* constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
* this.val = (val===undefined ? 0 : val)
* this.left = (left===undefined ? null : left)
* this.right = (right===undefined ? null : right)
* }
* }
*/
/**
* 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
*
*
* @param pRoot TreeNode类
* @return bool布尔型
*/
export function isSymmetrical(pRoot: TreeNode): boolean {
// write code here
function help(nodeLeft, nodeRight) {
if(nodeLeft === null && nodeRight === null) return true
if(nodeLeft === null || nodeRight === null || nodeLeft.val !== nodeRight.val) return false
return help(nodeLeft.left, nodeRight.right) && help(nodeLeft.right, nodeRight.left)
}
return help(pRoot, pRoot)
}
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