Merge pull request #1117 from skahk/master

Add merging of two Binary Search Trees

Tree/binary_search_tree/c++/merge_two_binary_search_tree.cpp

@@ -0,0 +1,117 @@
+#include <iostream>
+using namespace std;
+
+
+/*
+This represents the structure of the node of the Binary Search Tree.
+*/
+
+
+struct node
+{
+    node * left;
+    node * right;
+    int data;
+};
+
+
+/*
+This function adds new data into binary search tree (BST). 
+It takes root of the tree as parameter along with the new data to be inserted.
+*/
+
+
+node * add(node * root,int val)
+{
+    if(root == NULL)
+    {
+        node * newNode = new node;
+        newNode->data = val;
+        newNode->left=NULL;
+        newNode->right=NULL;
+        return newNode;
+    }
+    if(val > root->data)
+        root->right=add(root->right,val);
+    else
+        root->left=add(root->left,val);
+    return root;
+}
+
+
+/*
+This function traverses the second tree and adds its nodes to tree 1.
+It takes roots of tree 1 and tree 2 as parameters.
+*/
+
+
+node * merge(node * root1,node * root2)
+{
+    if(root2==NULL)
+        return root1;
+    merge(root1,root2->left);
+    add(root1,root2->data);
+    merge(root1,root2->right);
+}
+
+
+/*
+This function prints the inorder traversal of the BST thus printing
+a list of entered values in ascending order.It takes the root node as a parameter.
+*/
+
+
+void print_inorder(node *root)
+{
+    if(root==NULL)
+    return;
+    print_inorder(root->left);
+    cout<<root->data<<" ";
+    print_inorder(root->right);
+
+}
+
+int main()
+{
+    node * root1 =NULL;
+    node * root2 =NULL;
+
+    //  Insertion into tree1
+    root1=add(root1,12);
+    root1=add(root1,30);
+    root1=add(root1,2);
+    root1=add(root1,15);
+    root1=add(root1,6);
+    root1=add(root1,54);
+    root1=add(root1,27);
+
+    //Printing result
+    print_inorder(root1);
+    cout<<"\n";
+
+
+    //  Insertion into tree2
+    root2=add(root2,30);
+    root2=add(root2,23);
+    root2=add(root2,12);
+    root2=add(root2,43);
+    root2=add(root2,33);
+    root2=add(root2,62);
+    root2=add(root2,31);
+
+    //Printing result
+    print_inorder(root2);
+    cout<<"\n";
+
+
+    //  Merging the two trees
+
+    merge(root1,root2);
+
+
+    //  Printing merged tree
+
+    print_inorder(root1);
+
+    return 0;
+}