text: Print cousins of a given node in Binary Tree | C program to print cousins of a node ; A Binary Tree Node ; A utility function to create a new Binary Tree Node ; It returns level of the node if it is present in tree , otherwise returns 0. ; base cases ; If node is present in left subtree ; If node is not present in left subtree ; Print nodes at a given level such that sibling of node is not printed if it exists ; Base cases ; If current node is parent of a node with given level ; Recur for left and right subtrees ; This function prints cousins of a given node ; Get level of given node ; Print nodes of given level . ; Driver Program to test above functions
code: #include <stdio.h> NEW_LINE #include <stdlib.h> NEW_LINE struct Node { int data ; Node * left , * right ; } ; Node * newNode ( int item ) { Node * temp = new Node ; temp -> data = item ; temp -> left = temp -> right = NULL ; return temp ; } int getLevel ( Node * root , Node * node , int level ) { if ( root == NULL ) return 0 ; if ( root == node ) return level ; int downlevel = getLevel ( root -> left , node , level + 1 ) ; if ( downlevel != 0 ) return downlevel ; return getLevel ( root -> right , node , level + 1 ) ; } void printGivenLevel ( Node * root , Node * node , int level ) { if ( root == NULL level < 2 ) return ; if ( level == 2 ) { if ( root -> left == node root -> right == node ) return ; if ( root -> left ) printf ( " % d ▁ " , root -> left -> data ) ; if ( root -> right ) printf ( " % d ▁ " , root -> right -> data ) ; } else if ( level > 2 ) { printGivenLevel ( root -> left , node , level - 1 ) ; printGivenLevel ( root -> right , node , level - 1 ) ; } } void printCousins ( Node * root , Node * node ) { int level = getLevel ( root , node , 1 ) ; printGivenLevel ( root , node , level ) ; } int main ( ) { Node * root = newNode ( 1 ) ; root -> left = newNode ( 2 ) ; root -> right = newNode ( 3 ) ; root -> left -> left = newNode ( 4 ) ; root -> left -> right = newNode ( 5 ) ; root -> left -> right -> right = newNode ( 15 ) ; root -> right -> left = newNode ( 6 ) ; root -> right -> right = newNode ( 7 ) ; root -> right -> left -> right = newNode ( 8 ) ; printCousins ( root , root -> left -> right ) ; return 0 ; }