Leetcode--Path Sum

Title Description:


Given a binary tree and a sum, determine if the tree has a root-to-leaf path such this 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.




is from the root to the leaf, to determine if there is a path to sum.


Ideas:


A typical DFS problem, which accumulates the current number of nodes when traversing.


Implementation code:

public bool Haspathsum (TreeNode root, int sum) {        Find (root, 0, sum);        return found;    }        private bool found = false;        private void Find (TreeNode node, int sum, int target) {        if (found | | node = = NULL) {            return;        }        if (Node.left = = NULL && Node.right = = null) {if (sum + node.val = = target) {            found = true;        }}                        Find (node.left, sum + node.val, target);        Find (node.right, sum + node.val, target);    }

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Leetcode--Path Sum