题解 | #二叉树的镜像#

/*
 * function TreeNode(x) {
 *   this.val = x;
 *   this.left = null;
 *   this.right = null;
 * }
 */
/**
 * 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 TreeNode类
 */
function Mirror(pRoot) {
    return bfs(pRoot);
}

function dfs(root) {
    if (!root) {
        return root;
    }

    const temp = root.left;
    root.left = root.right;
    root.right = temp;

    dfs(root.left);
    dfs(root.right);

    return root;
}

function bfs(root) {
    if (!root) {
        return root;
    }

    const queue = [root];

    while (queue.length) {
        const node = queue.shift();

        const temp = node.left;
        node.left = node.right;
        node.right = temp;

        node.left && queue.push(node.left);
        node.right && queue.push(node.right);
    }

    return root;
}

module.exports = {
    Mirror: Mirror,
};