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 andsum = 22,
5
/ \
4 8
/ / \
11 13 4
/ \ \
7 2 1
return true, as there exist a root-to-leaf path5->4->11->2which sum is 22.
class Solution {
public:
bool hasPathSum(TreeNode *root, int sum) {
if(root==NULL)
return false;
__getPathSum( root, sum, 0);
return m_Flag;
}
private:
bool m_Flag=false;
void __getPathSum(TreeNode *root, int sum, int PathSum){
if(root->left==NULL && root->right==NULL){
if(PathSum+root->val==sum)
m_Flag=true;
return;
}
if(root->left!=NULL)
__getPathSum( root->left, sum, PathSum+root->val);
if(root->right!=NULL)
__getPathSum( root->right, sum, PathSum+root->val);
}
};