Below is the complete working C code with all operations in Binary Search Tree.

#include<stdio.h> #include<malloc.h> struct bst { int info; struct bst *left; struct bst *right; }; void delete(struct bst *root, int key); struct bst *find_min(struct bst *node); struct bst *find_max(struct bst *node); struct bst *insert(struct bst *node, int key); void print_postorder(struct bst *root); void print_preorder(struct bst *root); void print_inorder(struct bst *root); int height(struct bst *root); //deleting the element which handles three cases //1. deleting node has no leaf nodes //2. deleting node has one child(left or right) //3. deleting node has two childs void delete(struct bst *root, int key) { struct bst *current; struct bst *prev; int found = 0; if(root == NULL) { printf("The BST is empty\n"); return; } current = root; while(current!=NULL) { if(current->info == key) { found = 1; break; } else { prev = current; if(current->info >= key) current = current->left; else current = current->right; } } if(!found) { printf("given key element is not in the BST\n"); return; } //leaf node , no left n right childs if((current->left == NULL) && (current->right == NULL)) { if(prev->left == current) prev->left = NULL; else prev->right = NULL; free(current); } //single child node (either left or right child) if(current->left == NULL && current->right != NULL) { if(prev->left == current) prev->left = current->right; else prev->right = current->right; free (current); } if(current->right == NULL && current->left!=NULL) { if(prev->left = current) prev->left = current->left; else prev->right = current->left; free(current); } // need to handle the very complex case(node with both left n right childs) if(current->left != NULL && current->right != NULL) { struct bst *tmp = current->right; if(tmp->left == NULL && tmp->right == NULL) { current->info = tmp->info; free(tmp); current->right = NULL; } else if(current->right->left != NULL) { struct bst *left_current = current->right; struct bst *left_current_prev = current->right->left; while(left_current->left != NULL) { left_current_prev = left_current; left_current = left_current->left; } current->info = left_current->info; free(left_current); left_current_prev->left = NULL; } else { struct bst *temp; temp = current->right; current->info = temp->info; current->right = temp->right; free(temp); } } } //finding the min value struct bst *find_min(struct bst *node) { if(node == NULL) return NULL; if(node->left == NULL) return node; else return find_min(node->left); } //finding the max value struct bst *find_max(struct bst *node) { if(node!=NULL) { while(node->right!=NULL) node = node->right; } return node; } //adding the new element to the BST struct bst *insert(struct bst *node, int key) { if(node == NULL) { //creating the new node with the key and left n right sub nodes empty node = (struct bst *)malloc(sizeof(struct bst)); node->info = key; node->left = node->right = NULL; } else if(node->info >= key) node->left = insert(node->left, key); else node->right= insert(node->right, key); return node; } //printing post order (LRP) void print_postorder(struct bst *root) { struct bst *temp = root; if(temp!=NULL) { print_postorder(temp->left); print_postorder(temp->right); printf("%d ",temp->info); } } //printing preorder(PLR) void print_preorder(struct bst *root) { struct bst *temp = root; if(temp!=NULL) { printf("%d ",temp->info); print_preorder(temp->left); print_preorder(temp->right); } } //printing inorder (LPR) void print_inorder(struct bst *root) { struct bst *temp = root; if(temp!=NULL) { print_inorder(temp->left); printf("%d ",temp->info); print_inorder(temp->right); } } // to find the height of the tree int height(struct bst *root) { struct bst *temp = root; int leftH = 0; int rightH = 0; if(temp == NULL) return 0; if(temp->left) leftH = height(temp->left); if(temp->right) rightH = height(temp->right); return leftH >rightH ? leftH+1 : rightH+1; } int main() { struct bst *root=NULL; struct bst *tmp=NULL; int i,n,key,option; printf("Enter the no. elements in the BST\n"); scanf("%n",&n); printf("Enter the list of elements in the BST\n"); for(i=0;i<n;i++) { scanf("%d",&key); root = insert(root,key); } printf("Below are the possible opetaions you can performe in the above created BST\n"); printf("1. Insert\n2. Delete\n3. In-Order\n4. Pre-Order\n5. Post-Order\n6. Find Minimum\n7. Find Max\n8. height\n other value for exit"); scanf("%d,&option"); while(1) { switch(option) { case 1: printf("Enter the valeu to insert into the BST\n"); scanf("%d",&key); root = insert(root,key); break; case 2: printf("Enter the value to delete from the BST\n"); scanf("%d",&key); delete(root,key); break; case 3: print_inorder(root); break; case 4: print_preorder(root); break; case 5: print_postorder(root); break; case 6: if(tmp) printf("Min value in BST is %d\n",tmp->info); break; case 7: tmp = find_max(root); if(tmp) printf("Max value in BST is %d\n",tmp->info); break; case 8: printf("height of the BST is %d\n",height(root)); break; default: return 0; break; } printf("Below are the possible opetaions you can performe in the above created BST\n"); printf("1. Insert\n2. Delete\n3. In-Order\n4. Pre-Order\n5. Post-Order\n6. Find Minimum\n7. Find Max\n8. height\n other value for exit"); scanf("%d,&option"); } }