diff --git a/cpp/2205/220530-CN.cpp b/cpp/2205/220530-CN.cpp new file mode 100644 index 0000000..5be4888 --- /dev/null +++ b/cpp/2205/220530-CN.cpp @@ -0,0 +1,28 @@ +struct TreeNode { + int val; + TreeNode* left; + TreeNode* right; + explicit TreeNode(int x, TreeNode* left = nullptr, TreeNode* right = nullptr) : val(x), left(left), right(right) {} +}; + +/** + * 1022. Sum of Root To Leaf Binary Numbers + * You are given the root of a binary tree where each node has a value 0 or 1. Each root-to-leaf path represents a binary number starting with the most significant bit. + * For example, if the path is 0 -> 1 -> 1 -> 0 -> 1, then this could represent 01101 in binary, which is 13. + * For all leaves in the tree, consider the numbers represented by the path from the root to that leaf. Return the sum of these numbers. + * The test cases are generated so that the answer fits in a 32-bits integer. + * + * Refer: 220111.cpp + */ + +class Solution { +public: + int sumRootToLeaf(TreeNode* root, int sum = 0) { + if (!root) + return 0; + const int ans = (sum << 1) + root->val; + if (!root->left && !root->right) + return ans; + return sumRootToLeaf(root->left, ans) + sumRootToLeaf(root->right, ans); + } +};