Leetcode 112. Path Sum

题目：解法：简单递归

题目：

解法：简单递归

class Solution: def hasPathSum(self, root: TreeNode, sum: int) -> bool: def helper(node,curr_sum): if not node.left and not node.right: return curr_sum+node.val == sum flag = False if node.left: flag = flag or helper(node.left,curr_sum+node.val) if node.right: flag = flag or helper(node.right,curr_sum+node.val) return flag if not root: return False return helper(root,0)

C++版本：

class Solution { public: bool hasPathSum(TreeNode* root, int sum) { if (!root) return false; return helper(root,0,sum); } bool helper(TreeNode* node,int curr_sum,int sum){ if (!node->left && !node->right) return curr_sum+node->val==sum; bool flag=false; if (node->left){ flag = flag || helper(node->left,curr_sum+node->val,sum); } if (node->right){ flag = flag || helper(node->right,curr_sum+node->val,sum); } return flag; } };