#include <stdio.h>
#include <stdlib.h>
typedef struct treeNode
{
char key;
struct treeNode* left;
struct treeNode* right;
}treeNode;
typedef char element;
treeNode* insertNode(treeNode *p, char x)
{
treeNode *newNode;
if(p == NULL)
{
newNode = (treeNode*)malloc(sizeof(treeNode));
newNode -> key = x;
newNode -> left = NULL;
newNode -> right = NULL;
return newNode;
}
else if(x < p->key) p->left = insertNode(p->left,x);
else if(x > p->key) p->right = insertNode(p->right,x);
else printf("\n 이미 값은 키가 있습니다! \n");
return p;
}