145. Binary tree PostOrder Traversal

Author: SjxSubham

145. Binary tree PostOrder Traversal

@@ -0,0 +1,13 @@
+public:
+    void postorder(TreeNode* root,vector<int> &ans){
+        if(root == NULL) return;
+        postorder(root->left,ans);
+        postorder(root->right,ans);
+        ans.push_back(root->val);
+    }
+    vector<int> postorderTraversal(TreeNode* root) {
+        vector<int>ans;
+        postorder(root,ans);
+        return ans;
+    }
+};