LeetCode/Easy/path-sum/solution.cpp

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() : val(0), left(nullptr), right(nullptr) {}
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
    TreeNode(int x, TreeNode *left, TreeNode *right)
        : val(x), left(left), right(right) {}
};

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