Small code learns BST simple C language version from the source

  /********************************  Operating Environment:http://www.anycodes.cn/zh/  Original:/http blog.csdn.net/u014488381/article/details/41719765/  Two binary sorting tree Lookup algorithm C code implementation   modification to direct test   pending C + + class package version  **** /#include  <stdio.h> #include  <stdlib.h>typedef int  elemtype;typedef struct bitnode{elemtype data;struct bitnode *lchild, * Rchild;} bitnode, *bitree;/*/inserts a node in a given BST, whose data field (value) is Element/*/void bstinsert ( BiTree *t,  elemtype element ) {/*/each insertion   opening space/*/if ( NULL == *t )  {(*t)  =  ( Bitree) malloc (sizeof (Bitnode));(*t)->data = element; (*t)->lchild =  (*t)->rchild  = null;} /*/based on binary search tree Properties/*/if ( element ==  (*t)->data )  return ; /*/does not allow duplicate data, If you encounter a direct non-processing/*/else if ( element <  (*t)->data )  bstinsert ( & (*t) Lchild, element );     else                        bstinsert ( & (*t)->rchild,  element );} /*/Create BST/*/VOID&NBSP;CREATEBST ( BiTree *t, Elemtype *a, int n ) {(*t)  =  null;for ( int i=0; i<n; i++ ) Bstinsert ( t, a[i] );} /*/bst Recursive lookup/*/void searchbst ( BiTree t, Elemtype key ) {bitree p;   p = t;if ( p )  {if ( key == p->data ) printf ("Find success!\n"); Else if (  (key < p->data)  &&  (null != p->lchild)   ) Searchbst ( p->lchild , key ); Else if (  (key > p->data)   &&  (null != p->rchild)  ) Searchbst ( p->rchild , key ); Elseprintf ("No this element!\n ");}} /*/bst Iteration Find/*/void _searchbst ( BiTree t, Elemtype key ) {bitree p;   p = t;while ( NULL != p && key != p->data )  /*/nodes exist and values are unequal/*/{if ( key < p->data )   p = p->lchild  ; else          p = p->rchild ;} /*/  out of the loop after the  p pointer always points to the found element   or   The empty node under the leaf node/*/if ( NULL != p )  printf (" Find Success!\n ");  else        printf (" No This element!\n ");} /*/BST node deletion      This binary tree content focus/*/void delbstnode ( bitree t, elemtype key  ) {bitree p, q;p = t; elemtype temp;/*/  first traverse to find this element/*/while ( null != p && key != p- >data )  {q = p; /*/ q is always above the node p (q is always the father when P is not the root node)              p is the element we're going to delete./*/if ( key < p-> data ) p = p->lchild ;elsep = p->rchild ;} if ( NULL == p )   printf ("No This Element!\n"),/*/find element    There are a few things       1.         2.               3.      q             q                    q      /\           / \                  /  \        p  p        p   p                p     p              /     \              / \   / \               x       x            x   x  x  x /*/         else {/*/Case 1: The parent node of node p is Q, and p is a leaf node, it is deleted directly. /*/if ( NULL == p->lchild && NULL == p->rchild )  {if ( p == q->lchild )  q->lchild = null;if ( p == q-> rchild )  q->rchild = null;free (p);p  = NULL;} /*/Case 2: The parent node of node p is Q, and P has only Zuozi or only right subtree, then the left subtree or right subtree of p can be changed directly to the left or right subtree of the parent node Q. /*/else if (  (null == p->rchild && null != p->lchild)  )  {/*/p only left dial hand tree/*/if ( p == q->lchild ) q->lchild = p->lchild  ;else if ( p == q->rchild ) Q->rchild = p->lchild ;free (p );p  = null;} Else if ( NULL == p->lchild && NULL != p->rchild )  {/*/p only right subtree/*/if ( p == q->lchild ) q->lchild = p->rchild ;if (  p == q->rchild ) Q->rchild = p->rchild ;free (p);p  = null ;} /*/Case 3: The parent node of node p is Q, and P has both Zuozi and right subtree. This code uses direct precursor (or direct successor) here is the largest element in the left subtree/*/else if ( null != p->lchild && null  != p->rchild )  {BiTree s, sParent;sParent = p;s =  Sparent->lChild ;while ( NULL != s->rchild ) {/*/found the direct precursor of P/*/sparent = s;s =  s->rchild ;      /*/left dial Hand Tree The largest is always in the left sub-tree in the bottom right corner/*/}temp = s-> data ;    /*/this time  s is pointing to the largest right lower leaf node   for the general situation 1  directly delete/*/delbstnode ( t,  temp );p->data = temp;   /*/finally change the data of P that was originally to be deleted to the deletion of temp/*/}}}/*/pending version   The beauty of the Bst/*/void printbst sequence traversal print ( BiTree t ) {if ( t )  {printbst ( t-> lchild );p rintf ("%d ",  t->data); Printbst ( t->rchild );}} Void use () {int n;int *a; elemtype key; bitree t;printf ("Please enter the node number of the binary lookup tree: \ n"); scanf ("%d",  &n);a =  (int *) malloc (sizeof (int) * N);p rintf ("Please input binary tree node data: \ n"); for ( int i=0; i<n; i++ ) scanf ("%d",  &a[i]); Createbst ( &t, a, n );p rintf ("The current binary lookup tree's middle order traversal result is: \ n"); Printbst ( t );p Rintf ("\n##############################################\n");p rintf ("Please enter the element to find: \ n"); scanf ("%d",  &key); printf ("BST recursive lookup result: \ n"); Searchbst ( t, key );//recursively find printf ("##############################################\n");p rintf (" Please enter the element to be deleted: \ n "), scanf ("%d ",  &key);D Elbstnode ( t, key );p rintf (" The current binary lookup tree's middle order traversal result is: \ n "); Printbst ( t );p rintf ("\n##############################################\n");p rintf ("Please enter the element you want to find: \ n"); scanf ("%d",  &key);p rintf ("BST iterative lookup results: \ n"); _searchbst ( t, key );//Iteration Lookup  }void  Test () {Int n;  elemtype key;   bitree t;    int  a[]={5,8,2,1,4,7,9,6,3};p rintf ("Please enter the node number of the binary lookup tree: \ n");     n=9;printf ("Please enter the node data for the binary tree: \ n"); Createbst ( &t, a, n );p rintf ("The current binary lookup tree's middle order traversal result is: \ n"); Printbst ( t );p rintf ("\n##############################################\n");p rintf ("Please enter the element you want to find: \ n"); key=8;printf ("BST recursive lookup result: \ n"); SearchbST ( t, key );//recursively find printf ("##############################################\n");p rintf ("Please enter the element to be deleted : \ n ");  key=5;delbstnode ( t, key );p rintf (" The current binary lookup tree's middle order traversal result is: \ n "); Printbst ( t );p rintf ("\n##############################################\n");p rintf ("Please enter the element you want to find: \ n");  key=5;printf ("BST iterative lookup results: \ n"); _searchbst ( t, key );//Iteration Lookup  }int main (void) {printf ("hello,c world of anycodex!\n"); test (); return exit_success;}

Small code learns BST simple C language version from the source