zoukankan      html  css  js  c++  java
  • Path Sum

    Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

    For example:
    Given the below binary tree and sum = 22,

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

    return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.

     1 /**
     2  * Definition for binary tree
     3  * struct TreeNode {
     4  *     int val;
     5  *     TreeNode *left;
     6  *     TreeNode *right;
     7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
     8  * };
     9  */
    10 class Solution {
    11 public:
    12     bool hasPathSum(TreeNode *root, int sum) {
    13         
    14         if(root == NULL)
    15             return false;
    16             
    17         int tempSum = 0;
    18         int flag = 0;
    19         pathSum(root, tempSum, sum, flag);
    20         if(flag == 1)
    21             return true;
    22         else
    23             return false;
    24     }
    25     
    26     void pathSum(TreeNode *root, int tempSum, int sum, int &flag)
    27     {
    28         if(root != NULL)
    29         {
    30             if(root->left == NULL && root->right == NULL)
    31             {
    32                 tempSum += root->val;
    33                 if(tempSum == sum)
    34                     flag = 1;
    35                 
    36                 return;
    37             }
    38         
    39             else
    40             {
    41                 tempSum += root->val;
    42                 pathSum(root->left, tempSum, sum, flag);
    43                 pathSum(root->right, tempSum, sum, flag);
    44             }
    45         }
    46     }
    47 };
  • 相关阅读:
    向eureka注册正确的ip地址
    sleuth + zipkin 链路分析
    Yii2的整体结构概览
    Redis实现消息队列
    Redis使用场景梳理
    redis基础知识
    TCP服务
    数据结构-队列
    看见
    线性表的链式存储结构
  • 原文地址:https://www.cnblogs.com/YQCblog/p/3970191.html
Copyright © 2011-2022 走看看