Merge pull request #409 from malleshamshivs/master

Created Serialize and Deserialize Binary Tree.cpp

Author: amritansh22

Serialize and Deserialize Binary Tree.cpp

@@ -0,0 +1,103 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+
+ // Definition for a binary tree node.
+  struct TreeNode {
+     int val;
+     TreeNode *left;
+     TreeNode *right;
+     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+  };
+ 
+class Codec {
+public:
+
+    
+    string serialize(TreeNode* root) // Encodes a tree to a single string
+    {
+       string s="";
+        if(root==NULL)//Wherever the root is NULL,simply add "X ";
+            return "X ";
+        s+=(to_string(root->val)+" ");//Add the value string,then space and got to left and then right
+        s+=serialize(root->left);
+        s+=serialize(root->right);
+        return s;
+    }
+
+    
+    TreeNode* func(string data,int& ind)// Decodes your encoded data to tree.
+    {
+        if((data[ind]=='X')||(ind>=data.length()))//If the value at index is 'X',that implies the node was null
+        {
+            ind+=2;
+            return NULL;
+        }
+        string sx="";
+        while((ind<data.length())&&(data[ind]!=' '))//To get the value at that node
+        {
+            sx+=data[ind];
+            ind++;
+        }
+        ind++;
+        int temp1=stoi( sx );
+        TreeNode* nx=new TreeNode(temp1);//Add this node and process for left and right 
+        nx->left=func(data,ind);
+        nx->right=func(data,ind);
+        return nx;
+    }
+    
+    TreeNode* deserialize(string data) {
+        int ind=0;
+        return func(data,ind);//Calling the function with indices
+    }
+};//End of Codec Class
+
+void inorder(TreeNode* temp)//Inorder traversal of the tree
+{
+    if(temp==NULL)
+      return ;
+    inorder(temp->left);
+    cout<<temp->val<<" ";
+    inorder(temp->right);
+    return ;
+}
+
+int main()
+{
+    int n;
+    cin>>n;//Number of nodes in full binary tree.
+    vector<int> v(n);
+    for(int i=0;i<n;i++)//Taking input of the tree as a level-order-vector and make it full binary tree by adding value -1 at null values
+      cin>>v[i];
+      vector<TreeNode* > temp(n);
+    for(int i=0;i<n;i++)//Creating the nodes
+    {
+        if(v[i]==-1)
+          temp[i]=NULL;
+        else
+         temp[i]=new TreeNode(v[i]);
+    }
+    for(int i=0;i<n;i++)//Creating the binary tree by adding links
+    {
+        if(temp[i]!=NULL)
+        {
+            temp[i]->left=temp[2*i+1];
+            temp[i]->right=temp[2*i+2];
+        }
+    }
+    
+    Codec codec;//Object Creation
+    TreeNode* head=codec.deserialize(codec.serialize(temp[0]));//Passing temp[0] as root parameter
+      cout<<"Inorder Traversal is:"<<endl;
+      inorder(head);//Checking whether the process went correct by printing the values of the tree in inorder fashion
+     return 0;
+    
+}
+
+//Eg input :-
+// 15
+//1 2 3 -1 -1 5 4 -1 -1 -1 -1 -1 -1 -1 -1
+//Output:-
+//Inorder Traversal is:
+//2 1 5 3 4