Binary Search Tree (BST) : Finding Leaves : C Code

 Binary Search Tree (BST) : Finding Leaves : C Code

The following C code prints all the leaves nodes of a Binary Search Tree. A leaf-node is a node which has not left or right child. The code first scans the root node and looks whether it has a left and right child or not. If the condition is satisfied, it  is a leave node or else we recursively examine the left and right child.

#include<stdlib.h>
#include<stdio.h>
struct binaryTree {
   int key;
   struct binaryTree *right, *left;
};

typedef struct binaryTree node;

void insert(node **tree, int val);
void printLeaves(node *root);

int main() {
   node *root;
   int i,val,search;
   root = NULL;
   while(1) {
      printf("\n Enter the value (-1 to exit):");
      scanf("%d",&val);   
      if( val == -1)
          break;
      insert(&root, val);
   }
  
   printLeaves(root);
   printf("\n");
   
   return 0;
}
void printLeaves(node *root) {
    if (root->right == NULL && root->left == NULL) {
        printf("\n Leaf Node: %d",root->key);
        return;
        }
    if(root->right != NULL)    
        printLeaves(root->right);
    if(root->left != NULL)   
    printLeaves(root->left);
    }
void insert(node **tree, int val) {
   if((*tree) == NULL) {
      *tree = (node *)malloc(sizeof(node));
      (*tree)->key = val;
      (*tree)->right=(*tree)->left=NULL;
      return;
   }
   if(val < (*tree)->key)
      insert(&(*tree)->left, val);
   else if(val > (*tree)->key)
      insert(&(*tree)->right, val);
    }