[leetcode] Path Sum

最新推荐文章于 2020-07-07 13:07:47 发布

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最新推荐文章于 2020-07-07 13:07:47 发布

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分类专栏： C C++ leetcode

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解法一：

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool hasPathSum(TreeNode *root, int sum) {
        if(root==NULL)
            return false;
        if(root->left==NULL&&root->right==NULL)
            return sum==root->val;
        return hasPathSum(root->left,sum-root->val)||hasPathSum(root->right,sum-root->val);
    }
};

解法二：

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:

    bool hasPathSum(TreeNode *root,int sum,int curSum){
        if(root==NULL)
            return false;
        curSum+=root->val;
        if(root->left==NULL&&root->right==NULL)
            return sum==curSum;
        return hasPathSum(root->left,sum,curSum)||hasPathSum(root->right,sum,curSum);
    }

    bool hasPathSum(TreeNode *root, int sum) {
        return hasPathSum(root,sum,0);
    }

};