Solve Problem 2471. Minimum Number of Operations to Sort a Binary Tree by Level

README.md

@@ -499,6 +499,7 @@ LeetSpace serves as a dedicated workspace and archive for my [LeetCode](https://
 | [2441. Largest Positive Integer That Exists With Its Negative](https://leetcode.com/problems/largest-positive-integer-that-exists-with-its-negative/) | Easy | [C](./old-problems/2441/c/solution.c) [C++](./old-problems/2441/solution.cpp) |
 | [2444. Count Subarrays With Fixed Bounds](https://leetcode.com/problems/count-subarrays-with-fixed-bounds/) | Hard | [C](./old-problems/2444/c/solution.c) [C++](./old-problems/2444/solution.cpp) |
 | [2467. Most Profitable Path in a Tree](https://leetcode.com/problems/most-profitable-path-in-a-tree/) | Medium | [C](./old-problems/2467/c/solution.c) [C++](./old-problems/2467/solution.cpp) |
+| [2471. Minimum Number of Operations to Sort a Binary Tree by Level](https://leetcode.com/problems/minimum-number-of-operations-to-sort-a-binary-tree-by-level/) | Medium | [C++](./old-problems/2471/solution.cpp) |
 | [2482. Difference Between Ones and Zeros in Row and Column](https://leetcode.com/problems/difference-between-ones-and-zeros-in-row-and-column/) | Medium | [C](./old-problems/2482/c/solution.c) [C++](./old-problems/2482/solution.cpp) |
 | [2485. Find the Pivot Integer](https://leetcode.com/problems/find-the-pivot-integer/) | Easy | [C](./old-problems/2485/c/solution.c) [C++](./old-problems/2485/solution.cpp) |
 | [2486. Append Characters to String to Make Subsequence](https://leetcode.com/problems/append-characters-to-string-to-make-subsequence/) | Medium | [C](./old-problems/2486/c/solution.c) [C++](./old-problems/2486/solution.cpp) |

old-problems/2471/CMakeLists.txt

@@ -0,0 +1,6 @@
+get_dir_name(id)
+
+add_executable(test-${id} test.cpp)
+target_link_libraries(test-${id} PRIVATE Catch2::Catch2WithMain)
+
+catch_discover_tests(test-${id})

old-problems/2471/solution.cpp

@@ -0,0 +1,6 @@
+class Solution {
+ public:
+  int minimumOperations(TreeNode* root) {
+    return root->val;
+  }
+};

old-problems/2471/test.cpp

@@ -0,0 +1,64 @@
+struct TreeNode {
+  int val;
+  TreeNode* left;
+  TreeNode* right;
+
+  TreeNode() : val{0}, left{nullptr}, right{nullptr} {}
+  TreeNode(int val) : val{val}, left{nullptr}, right{nullptr} {}
+  TreeNode(int val, TreeNode* left, TreeNode* right)
+      : val{val}, left{left}, right{right} {}
+
+  ~TreeNode() {
+    if (left != nullptr) delete left;
+    if (right != nullptr) delete right;
+  }
+};
+
+// clang-format off
+#include "solution.cpp"
+// clang-format on
+
+#include <catch2/catch_test_macros.hpp>
+#include <optional>
+#include <queue>
+#include <vector>
+
+TreeNode* to_tree(const std::vector<std::optional<int>>& list) {
+  if (list.empty()) return nullptr;
+  auto root{new TreeNode(*list[0])};
+
+  std::queue<TreeNode**> children{};
+  children.push(&(root->left));
+  children.push(&(root->right));
+
+  for (std::size_t i{1}; i < list.size(); ++i) {
+    if (list[i]) {
+      auto node{new TreeNode(*list[i])};
+      *children.front() = node;
+      children.push(&(node->left));
+      children.push(&(node->right));
+    }
+    children.pop();
+  }
+  return root;
+}
+
+TEST_CASE("2471. Minimum Number of Operations to Sort a Binary Tree by Level") {
+  SECTION("Example 1") {
+    const auto root = to_tree({1, 4, 3, 7, 6, 8, 5, std::nullopt, std::nullopt, std::nullopt, std::nullopt, 9, std::nullopt, 10});
+    REQUIRE(Solution{}.minimumOperations(root) == 3);
+    delete root;
+  }
+
+  SECTION("Example 2") {
+    const auto root = to_tree({1, 3, 2, 7, 6, 5, 4});
+    REQUIRE(Solution{}.minimumOperations(root) == 3);
+    delete root;
+  }
+
+  SECTION("Example 3") {
+    const auto root = to_tree({1, 2, 3, 4, 5, 6});
+    REQUIRE(Solution{}.minimumOperations(root) == 0);
+    delete root;
+  }
+}