题解 | #合并二叉树#

/*
 * 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 t1 TreeNode类
 * @param t2 TreeNode类
 * @return TreeNode类
 */
function mergeTrees(t1, t2) {
    // write code here
    if (t1 && t2) {
        // 如果都存在
        let val = t1.val + t2.val;
        let left = mergeTrees(t1.left, t2.left);
        let right = mergeTrees(t1.right, t2.right);
        let newNode = new TreeNode(val);
        newNode.left = left;
        newNode.right = right;
        return newNode;
    }

    // 两棵子树在这个点存在任何一个，则不会为空
    return t1 || t2;
}
module.exports = {
    mergeTrees: mergeTrees,
};