add: 230314

cpp/2303/230314.cpp

@@ -0,0 +1,46 @@
+#include <functional>
+
+struct TreeNode {
+	int val;
+	TreeNode* left;
+	TreeNode* right;
+
+	explicit TreeNode(int x, TreeNode* left = nullptr, TreeNode* right = nullptr) : val(x), left(left), right(right) {}
+};
+
+/**
+ * 129. Sum Root to Leaf Numbers
+ *
+ * You are given the root of a binary tree containing digits from 0 to 9 only.
+ * Each root-to-leaf path in the tree represents a number.
+ * For example, the root-to-leaf path 1 -> 2 -> 3 represents the number 123.
+ * Return the total sum of all root-to-leaf numbers. Test cases are generated so that the answer will fit in a 32-bit integer.
+ * A leaf node is a node with no children.
+ */
+
+class Solution {
+public:
+	static int sumNumbers(const TreeNode* root) {
+		if (!root)
+			return 0;
+		int stack[16]{root->val}, ptr = 0, ans = 0;
+		std::function<void(const TreeNode*)> dfs = [&](const TreeNode* r) {
+			if (!r->left && !r->right) {
+				ans += stack[ptr];
+				return;
+			}
+			++ptr;
+			if (r->left) {
+				stack[ptr] = 10 * stack[ptr - 1] + r->left->val;
+				dfs(r->left);
+			}
+			if (r->right) {
+				stack[ptr] = 10 * stack[ptr - 1] + r->right->val;
+				dfs(r->right);
+			}
+			--ptr;
+		};
+		dfs(root);
+		return ans;
+	}
+};

cpp/2303/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2303)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2303 230314-CN.cpp)
+ADD_EXECUTABLE(2303 230314.cpp)