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.
Note: A leaf is a node with no children.
Example:
Given the below binary tree and sum = 22
,
return true, as there exist a root-to-leaf path 5->4->11->2
which sum is 22.
c
代码语言:javascript复制class Solution {
public:
bool hasPathSum(TreeNode* root, int sum) {
if(root==NULL)
return false;
else if(sum == root->val&&root->left==NULL&&root->right==NULL)
return true;
bool tagleft=false;
bool tagright=false;
if(root->left!=NULL)
tagleft = hasPathSum(root->left,sum-root->val);
if(root->right!=NULL)
tagright = hasPathSum(root->right,sum-root->val);
if(tagleft||tagright)
return true;
return false;
}
};