//144の続き//

struct tnode *createNode (char num)
{
struct tnode *node;
if ((node = malloc(sizeof(struct tnode))) == NULL) {
fprintf(stderr, "malloc\n");
exit(1);
}
node -> n = num;
node -> left = NULL;
node -> right = NULL;
return node;
}

struct tnode *insertNode (struct tnode *node, char num)
{
node -> n;
if (!node) {
node = createNode(num);
return node;
}

if (strcmp(char *num, char *node) > 0)
node -> left = insertNode(node -> left, num);

if (strcmp(char *num, char *node) < 0)
node -> right = insertNode(node -> right, num);

return node;
}