Create Postorder_Traversal.cpp

Tree Data Structure/Postorder_Traversal.cpp

@@ -0,0 +1,21 @@
+/*Given a binary tree, return the postorder traversal of its nodes’ values.*/
+
+
+vector<int> Solution::postorderTraversal(TreeNode* A) {
+    vector<int> Answer;
+    stack<TreeNode*> stac;
+    if(!A)return Answer;
+    stac.push(A);
+
+    while(!stac.empty()){
+        struct TreeNode * nod = stac.top();
+        Answer.push_back(nod -> val);
+        stac.pop();
+        if(nod -> left) stac.push(nod->left);
+        if(nod -> right) stac.push(nod->right);
+
+    }
+    reverse(Answer.begin(),Answer.end());
+    return Answer;
+
+}