Create main.cpp

Author: JawadSher

17 - Binary Tree Data Structure Problems/32 - Buring Tree/main.cpp

@@ -0,0 +1,80 @@
+class Solution {
+  public:
+    Node* createParentMapping(Node* root, int target, unordered_map<Node*, Node*>&nodeToParent){
+        Node* result = NULL;
+        queue<Node*> q;
+        q.push(root);
+        
+        nodeToParent[root] = NULL;
+        
+        while(!q.empty()){
+            Node* front = q.front();
+            q.pop();
+            
+            if(front -> data == target) result = front;
+            
+            if(front -> left){
+                nodeToParent[front -> left] = front;
+                q.push(front -> left);
+            }
+            
+            if(front -> right){
+                nodeToParent[front -> right] = front;
+                q.push(front -> right);
+            }
+        }
+        
+        return result;
+    }
+    
+    int burnTree(Node* root, unordered_map<Node*, Node*> &nodeToParent){
+        unordered_map<Node*, bool> visited;
+        queue<Node*> q;
+        
+        q.push(root);
+        visited[root] = true;
+        
+        int ans = 0;
+        
+        while(!q.empty()){
+            bool flag = false;
+            int size = q.size();
+            
+            for(int i = 0; i < size; i++){
+                Node* front = q.front();
+                q.pop();
+            
+                if(front -> left && !visited[front->left]){
+                    flag = true;
+                    q.push(front -> left);
+                    visited[front -> left] = true;
+                }
+                
+                if(front -> right && !visited[front -> right]){
+                    flag = true;
+                    q.push(front -> right);
+                    visited[front -> right] = true;
+                }
+                
+                if(nodeToParent[front] && !visited[nodeToParent[front]]){
+                    flag = true;
+                    q.push(nodeToParent[front]);
+                    visited[nodeToParent[front]] = true;
+                }
+            }
+            
+            if(flag == true) ans++;
+            
+        }
+        
+        return ans;
+    }
+    
+    int minTime(Node* root, int target) 
+    {
+        unordered_map<Node*, Node*> nodeToParent;
+        Node* targetNode = createParentMapping(root, target, nodeToParent);
+        
+        return burnTree(targetNode, nodeToParent);
+    }
+};