s0257

src/s0257_binary_tree_paths.cpp

@@ -0,0 +1,27 @@
+#include "s0257_binary_tree_paths.hpp"
+
+struct TreeNodeState_S0257 {
+  TreeNode* ptr;
+  string path;
+};
+
+vector<string> S0257::binaryTreePaths(TreeNode* root) {
+  queue<TreeNodeState_S0257> q;
+  vector<string> result{};
+  if (root) q.push(TreeNodeState_S0257{root, std::to_string(root->val)});
+  while (!q.empty()) {
+    TreeNodeState_S0257 front = q.front();
+    q.pop();
+    if (front.ptr->left == nullptr && front.ptr->right == nullptr)
+      result.push_back(front.path);
+    if (front.ptr->left)
+      q.push(TreeNodeState_S0257{
+          front.ptr->left,
+          front.path + "->" + std::to_string(front.ptr->left->val)});
+    if (front.ptr->right)
+      q.push(TreeNodeState_S0257{
+          front.ptr->right,
+          front.path + "->" + std::to_string(front.ptr->right->val)});
+  }
+  return result;
+}