103

Author: Ashish-kumar7

103.cpp

@@ -0,0 +1,54 @@
+class Solution {
+public:
+    vector<vector<int>> zigzagLevelOrder(TreeNode* root) {
+        vector<vector<int>>A;
+        if(root==NULL){
+            return A;
+        }
+        
+        stack<TreeNode*>q1;
+        stack<TreeNode*>q2;
+        
+          q1.push(root);
+
+        while(!q1.empty())
+        {
+        vector<int>B;
+        int sz1=q1.size();
+        while(sz1--){
+            TreeNode * node =q1.top();
+            q1.pop();
+            B.push_back(node->val);
+            if(node->left){
+                q2.push(node->left);
+            }
+            if(node->right){
+                q2.push(node->right);
+            }
+        }
+        if(B.size()!=0){
+        A.push_back(B);
+        }
+            B.clear();
+        int sz2=q2.size();
+            
+        while(sz2--){
+            TreeNode * node =q2.top();
+            q2.pop();
+            B.push_back(node->val);
+            if(node->right)
+            {
+                q1.push(node->right);
+            }
+            if(node->left)
+            {
+                q1.push(node->left);
+            }  
+        }
+        if(B.size()!=0){
+        A.push_back(B); 
+        }
+        }   
+        return A;
+    }
+};