题解 | #二叉树中和为某一值的路径(一)#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param root TreeNode类 
     * @param sum int整型 
     * @return bool布尔型
     */
    bool result = false;
    void dfs(TreeNode* root, long int sum,long int ans){
        if(root){
             dfs(root->left,sum,ans + root->val);
             dfs(root->right,sum,ans + root->val);
             if(root->left == NULL && root->right == NULL && ans + root->val == sum)
                 result = true;
        }
    }
    bool hasPathSum(TreeNode* root, long int sum) {
        if(root == NULL)
            return false;
        dfs(root,sum,0);
        return result;
    }
};