遞歸實現(xiàn)
- Runtime: 68 ms, faster than 94.35%
- Memory Usage: 37.1 MB, less than 27.88%
- 時間復雜度
- 空間復雜度
/**
* Definition for a binary tree node.
* function TreeNode(val, left, right) {
* this.val = (val===undefined ? 0 : val)
* this.left = (left===undefined ? null : left)
* this.right = (right===undefined ? null : right)
* }
*/
/**
* @param {TreeNode} root
* @return {TreeNode}
*/
var invertTree = function(root) {
if(!root) return null
let left = invertTree(root.left)
let right = invertTree(root.right)
root.left = right
root.right = left
return root
};
迭代實現(xiàn)
- Runtime: 76 ms, faster than 68.04%
- Memory Usage: 36.9 MB, less than 54.25%
- 時間復雜度
- 空間復雜度
硫椰，最壞情況下，隊列中包含樹中的所有節(jié)點
深度優(yōu)先遍歷方法實現(xiàn)
var invertTree = function(root) {
if(!root) return null
let queue = [root]
while(queue.length) {
let n = queue.length
let node = queue.shift()
let left = node.left
node.left = node.right
node.right = left
node.left && queue.push(node.left)
node.right && queue.push(node.right)
}
return root
};
