path-sum-112.cc

class Solution {
public:
  bool hasPathSum(TreeNode *root, int targetSum) {
    if (!root) {
      return false;
    }
    if (!root->left && !root->right && root->val == targetSum) {
      return true;
    }
    return hasPathSum(root->left, targetSum - root->val) ||
           hasPathSum(root->right, targetSum - root->val);
  }
};