43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 char * btree_find_depthFirst (btree root, int val, char *buf) { /*. TODO: Search the tree specified by "root" to find the first node that has a payload of "val", and return the string path from the root to that node, where an "L" in the path specifies take the left branch, and "R" specifies take the right branch, and a "*" says look here. The search should occur by first checking the payload at the root node, then checking the entire left sub-tree, then checking the entire right sub-tree The "buf" parameter provides a pointer to memory where the path can be stored. You may assume buf starts out with a 0x00 null string terminator at position 0. If "val" is not a payload of any node in the tree, a NULL pointer should be returned. 61 62 63 64 655 66 65 66 67 68 69 70 71 RECOMMENDED ALGORITHM - Recursive Search If the root is NULL, return NULL - value not found If the root payload matches val, add "*" to the end of buf and return. You found the result here - Make an rbuf local variable to hold the results of searching the sub-trees recursively. You may assume the path is less than 100 characters long. but be sure the first character of rbuf is 0x00. - Invoke btree_find_depthFirst recursively on the left sub-tree. If a result is found, add an "L" and the