IDEA2023.1.3破解,IDEA破解,IDEA 2023.1破解,最新IDEA激活码

路径总和

IDEA2023.1.3破解,IDEA破解,IDEA 2023.1破解,最新IDEA激活码

路径总和

给定一个二叉树和一个目标和,判断该树中是否存在根节点到叶子节点的路径,这条路径上所有节点值相加等于目标和。
说明: 叶子节点是指没有子节点的节点。

示例

给定如下二叉树,以及目标和sum = 22,返回true,因为存在目标和为22的根节点到叶子节点的路径5->4->11->2

              5
             / \
            4   8
           /   / \
          11  13  4
         /  \      \
        7    2      1

题解

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @param {number} sum
 * @return {boolean}
 */
var hasPathSum = function(root, sum) {
    return dfs(root, sum, 0); 
};

function dfs(root, sum, tmp){
    if(!root) return false;
    tmp = tmp + root.val;
    if(!root.left && !root.right) return tmp === sum ;
    return dfs(root.left, sum, tmp) || dfs(root.right, sum, tmp);
}

思路

深度优先遍历即可,首先处理边界条件,如果节点为null则直接返回false,之后将tmp值与节点值相加,如果此节点为根节点,那么就返回tmp是否与sum相等的判断,最后进行深度递归遍历,利用短路运算效应,在左子树为true的情况下不会再进行右子树的递归运算,在右子树为true的情况下会直接返回上层递归运算,这样即可实现路径总和的计算。

每日一题

https://github.com/WindrunnerMax/EveryDay

题源

https://leetcode-cn.com/problems/path-sum

文章永久链接:https://tech.souyunku.com/?p=39641


Warning: A non-numeric value encountered in /data/wangzhan/tech.souyunku.com.wp/wp-content/themes/dux/functions-theme.php on line 1154
赞(81) 打赏



未经允许不得转载:搜云库技术团队 » 路径总和

IDEA2023.1.3破解,IDEA破解,IDEA 2023.1破解,最新IDEA激活码
IDEA2023.1.3破解,IDEA破解,IDEA 2023.1破解,最新IDEA激活码

评论 抢沙发

大前端WP主题 更专业 更方便

联系我们联系我们

觉得文章有用就打赏一下文章作者

微信扫一扫打赏

微信扫一扫打赏


Fatal error: Uncaught Exception: Cache directory not writable. Comet Cache needs this directory please: `/data/wangzhan/tech.souyunku.com.wp/wp-content/cache/comet-cache/cache/https/tech-souyunku-com/index.q`. Set permissions to `755` or higher; `777` might be needed in some cases. in /data/wangzhan/tech.souyunku.com.wp/wp-content/plugins/comet-cache/src/includes/traits/Ac/ObUtils.php:367 Stack trace: #0 [internal function]: WebSharks\CometCache\Classes\AdvancedCache->outputBufferCallbackHandler() #1 /data/wangzhan/tech.souyunku.com.wp/wp-includes/functions.php(5109): ob_end_flush() #2 /data/wangzhan/tech.souyunku.com.wp/wp-includes/class-wp-hook.php(303): wp_ob_end_flush_all() #3 /data/wangzhan/tech.souyunku.com.wp/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters() #4 /data/wangzhan/tech.souyunku.com.wp/wp-includes/plugin.php(470): WP_Hook->do_action() #5 /data/wangzhan/tech.souyunku.com.wp/wp-includes/load.php(1097): do_action() #6 [internal function]: shutdown_action_hook() #7 {main} thrown in /data/wangzhan/tech.souyunku.com.wp/wp-content/plugins/comet-cache/src/includes/traits/Ac/ObUtils.php on line 367