Day 30 - LeetCode 100. Same Tree

LeetCode 100. Same Tree

題目

Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

翻譯

給定兩個二元樹，判斷這兩個樹的每一個節點中的值與節點位置是否都相同

想法

比較兩個數的val, 不相同或是子節點數不同就retun false, 直到都比完再return true

詳細參閱

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Code

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} p
 * @param {TreeNode} q
 * @return {boolean}
 */
var isSameTree = function (p, q) {
    // 都是空的
    if ( !p && !q ) {
        return true;
    }
    // p不存在q存在 或者 p存在q不存在
    if ( (!p && q) || (p && !q) ) {
        return false;
    }
    // val不相等
    if ( p.val !== q.val ) {
        return false;
    }
    //一直往下一層比較
    return isSameTree(p.left, q.left) && isSameTree(p.right, q.right)
};

Run