Initial commit

Easy/binary-tree-postorder-traversal/solution.cpp

@@ -0,0 +1,31 @@
+#include <vector>
+
+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 {
+  private:
+    void traverse(std::vector<int> &list, TreeNode *root) {
+        if (root == nullptr) {
+            return;
+        } else {
+            traverse(list, root->left);
+            traverse(list, root->right);
+            list.push_back(root->val);
+        }
+    }
+
+  public:
+    std::vector<int> postorderTraversal(TreeNode *root) {
+        std::vector<int> list;
+        traverse(list, root);
+        return list;
+    }
+};