Merge pull request #75 from krishna14kant/main

added bst program

CPP/bst.c

@@ -0,0 +1,359 @@
+# include <iostream>
+# include <cstdlib>
+using namespace std;
+struct nod//node declaration
+{
+   int info;
+   struct nod *l;
+   struct nod *r;
+}*r;
+class BST
+{
+   public://functions declaration
+   void search(nod *, int);
+   void find(int, nod **, nod **);
+   void insert(nod *, nod *);
+   void del(int);
+   void casea(nod *,nod *);
+   void caseb(nod *,nod *);
+   void casec(nod *,nod *);
+   void preorder(nod *);
+   void inorder(nod *);
+   void postorder(nod *);
+   void show(nod *, int);
+   BST()
+   {
+      r = NULL;
+   }
+};
+void BST::find(int i, nod **par, nod **loc)//find the position of the item
+{
+   nod *ptr, *ptrsave;
+   if (r == NULL)
+   {
+      *loc = NULL;
+      *par = NULL;
+      return;
+   }
+   if (i == r→info)
+   {
+      *loc = r;
+      *par = NULL;
+      return;
+   }
+   if (i < r→info)
+   ptr = r→l;
+   else
+   ptr = r→r;
+   ptrsave = r;
+   while (ptr != NULL)
+   {
+      if (i == ptr→info)
+      {
+         *loc = ptr;
+         *par = ptrsave;
+         return;
+      }
+      ptrsave = ptr;
+      if (i < ptr→info)
+      ptr = ptr→l;
+      else
+      ptr = ptr→r;
+   }
+   *loc = NULL;
+   *par = ptrsave;
+}
+void BST::search(nod *root, int data) //searching
+{
+   int depth = 0;
+   nod *temp = new nod;
+   temp = root;
+   while(temp != NULL)
+   {
+      depth++;
+      if(temp→info == data)
+      {
+         cout<<"\nData found at depth: "<<depth<<endl;
+         return;
+      }
+      else if(temp→info > data)
+      temp = temp→l;
+      else
+      temp = temp→r;
+   }
+   cout<<"\n Data not found"<<endl;
+   return;
+}
+void BST::insert(nod *tree, nod *newnode)
+{
+   if (r == NULL)
+   {
+      r = new nod;
+      r→info = newnode→info;
+      r→l= NULL;
+      r→r= NULL;
+      cout<<"Root Node is Added"<<endl;
+      return;
+   }
+   if (tree→info == newnode→info)
+   {
+      cout<<"Element already in the tree"<<endl;
+      return;
+   }
+   if (tree→info > newnode→info)
+   {
+      if (tree→l != NULL)
+      {
+         insert(tree→l, newnode);
+      }
+      else
+      {
+         tree→l= newnode;
+         (tree→l)→l = NULL;
+         (tree→l)→r= NULL;
+         cout<<"Node Added To Left"<<endl;
+         return;
+      }
+   }
+   else
+   {
+      if (tree→r != NULL)
+      {
+         insert(tree→r, newnode);
+      }
+      else
+      {
+         tree→r = newnode;
+         (tree→r)→l= NULL;
+         (tree→r)→r = NULL;
+         cout<<"Node Added To Right"<<endl;
+         return;
+      }
+   }
+}
+void BST::del(int i)
+{
+   nod *par, *loc;
+   if (r == NULL)
+   {
+      cout<<"Tree empty"<<endl;
+      return;
+   }
+   find(i, &par, &loc);
+   if (loc == NULL)
+   {
+      cout<<"Item not present in tree"<<endl;
+      return;
+   }
+   if (loc→l == NULL && loc→r == NULL)
+   {
+      casea(par, loc);
+      cout<<"item deleted"<<endl;
+   }
+   if (loc→l!= NULL && loc→r == NULL)
+   {
+      caseb(par, loc);
+      cout<<"item deleted"<<endl;
+   }
+   if (loc→l== NULL && loc→r != NULL)
+   {
+      caseb(par, loc);
+      cout<<"item deleted"<<endl;
+   }
+   if (loc→l != NULL && loc→r != NULL)
+   {
+      casec(par, loc);
+      cout<<"item deleted"<<endl;
+   }
+   free(loc);
+}
+void BST::casea(nod *par, nod *loc )
+{
+   if (par == NULL)
+{
+   r= NULL;
+}
+else
+{
+   if (loc == par→l)
+   par→l = NULL;
+   else
+   par→r = NULL;
+   }
+}
+void BST::caseb(nod *par, nod *loc)
+{
+   nod *child;
+   if (loc→l!= NULL)
+      child = loc→l;
+   else
+      child = loc→r;
+   if (par == NULL)
+   {
+      r = child;
+   }
+   else
+   {
+      if (loc == par→l)
+         par→l = child;
+      else
+         par→r = child;
+   }
+}
+void BST::casec(nod *par, nod *loc)
+{
+   nod *ptr, *ptrsave, *suc, *parsuc;
+   ptrsave = loc;
+   ptr = loc→r;
+   while (ptr→l!= NULL)
+   {
+      ptrsave = ptr;
+      ptr = ptr→l;
+   }
+   suc = ptr;
+   parsuc = ptrsave;
+   if (suc→l == NULL && suc→r == NULL)
+      casea(parsuc, suc);
+   else
+      caseb(parsuc, suc);
+   if (par == NULL)
+   {
+      r = suc;
+   }
+   else
+   {
+      if (loc == par→l)
+         par→l = suc;
+      else
+         par→r= suc;
+   }
+   suc→l = loc→l;
+   suc→r= loc→r;
+}
+void BST::preorder(nod *ptr)
+{
+   if (r == NULL)
+   {
+      cout<<"Tree is empty"<<endl;
+      return;
+   }
+   if (ptr != NULL)
+   {
+      cout<<ptr→info<<" ";
+      preorder(ptr→l);
+      preorder(ptr→r);
+   }
+}
+void BST::inorder(nod *ptr)//inorder traversal
+{
+   if (r == NULL)
+   {
+      cout<<"Tree is empty"<<endl;
+      return;
+   }
+   if (ptr != NULL)
+   {
+      inorder(ptr→l);
+      cout<<ptr→info<<" ";
+      inorder(ptr→r);
+   }
+}
+void BST::postorder(nod *ptr)//postorder traversal
+{
+   if (r == NULL)
+   {
+      cout<<"Tree is empty"<<endl;
+      return;
+   }
+   if (ptr != NULL)
+   {
+      postorder(ptr→l);
+      postorder(ptr→r);
+      cout<<ptr→info<<" ";
+   }
+}
+void BST::show(nod *ptr, int level)//print the tree
+{
+   int i;
+   if (ptr != NULL)
+   {
+      show(ptr→r, level+1);
+      cout<<endl;
+      if (ptr == r)
+         cout<<"Root→: ";
+      else
+      {
+         for (i = 0;i < level;i++)
+         cout<<" ";
+      }
+      cout<<ptr→info;
+      show(ptr→l, level+1);
+   }
+}
+int main()
+{
+   int c, n,item;
+   BST bst;
+   nod *t;
+   while (1)
+   {
+      cout<<"1.Insert Element "<<endl;
+      cout<<"2.Delete Element "<<endl;
+      cout<<"3.Search Element"<<endl;
+      cout<<"4.Inorder Traversal"<<endl;
+      cout<<"5.Preorder Traversal"<<endl;
+      cout<<"6.Postorder Traversal"<<endl;
+      cout<<"7.Display the tree"<<endl;
+      cout<<"8.Quit"<<endl;
+      cout<<"Enter your choice : ";
+      cin>>c;
+      switch(c)
+      {
+         case 1:
+            t = new nod;
+            cout<<"Enter the number to be inserted : ";
+            cin>>t→info;
+            bst.insert(r, t);
+            break;
+         case 2:
+            if (r == NULL)
+            {
+               cout<<"Tree is empty, nothing to delete"<<endl;
+               continue;
+            }
+            cout<<"Enter the number to be deleted : ";
+            cin>>n;
+            bst.del(n);
+            break;
+         case 3:
+            cout<<"Search:"<<endl;
+            cin>>item;
+            bst.search(r,item);
+            break;
+         case 4:
+            cout<<"Inorder Traversal of BST:"<<endl;
+            bst.inorder(r);
+            cout<<endl;
+            break;
+         case 5:
+            cout<<"Preorder Traversal of BST:"<<endl;
+            bst.preorder(r);
+            cout<<endl;
+            break;
+         case 6:
+            cout<<"Postorder Traversal of BST:"<<endl;
+            bst.postorder(r);
+            cout<<endl;
+            break;
+         case 7:
+            cout<<"Display BST:"<<endl;
+            bst.show(r,1);
+            cout<<endl;
+            break;
+         case 8:
+            exit(1);
+         default:
+            cout<<"Wrong choice"<<endl;
+      }
+   }
+}