#include <stdlib.h>
#include <stdio.h>

typedef struct elem* list;
typedef struct elem {
	int value;
	list next;
} elem;

typedef struct node* tree;
typedef struct node {
	int key;
	tree left, right;
} node;

void printTree(tree t); // Thank you Toni for putting your code online so I can steal it.


int f(list l) {
	while (l) {
		if (l->next == 0) return 1;
		int diff = l->value - l->next->value;
		if(diff > 1 || diff < -1)
			return 0;
		else
			l = l->next;
	}
	return -1;
}

void defol(tree *p) {
	if(!*p) return;
	// Basisfall
	if (!(*p)->left && !(*p)->right) //leaf
		*p = NULL; // freeing the leaf... eh.
	else {
		defol(&(*p)->left);
		defol(&(*p)->right);
	}
}


void main () {
	list el3 = malloc(sizeof(elem));
	el3->value = 45;
	el3->next = NULL;
	list el2 = malloc(sizeof(elem));
	el2->value = 43;
	el2->next = el3;
	list el1 = malloc(sizeof(elem));
	el1->value = 42;
	el1->next = el2;
	
	int isittrue = f(el1);
	
	printf("%d\n", isittrue);
	
	node* s = malloc(sizeof(node));
	s->key = 2;
		node* s1 = malloc(sizeof(node));
		s1->key = 3;
		s->left = s1;
			node* s11 = malloc(sizeof(node));
			s11->key = 2;
			s11->left = NULL;
			s11->right = NULL;
			s1->left = s11;
			node* s12 = malloc(sizeof(node));
			s12->key = 4;
			s11->left = NULL;
			s11->right = NULL;
			s1->right = s12;
		node* s2 = malloc(sizeof(node));
		s2->key = 1;
		s2->left = NULL;
		s2->left = NULL;
		s->right = s2;
	
	defol(&s);
	printTree(s);
}


// Stolen from http://wwwtcs.inf.tu-dresden.de/~dietze/2014w/aud/
// ... for purely academic reasons!

void printTreeHelper(tree t, int level, unsigned int branches) {
	int i;
	if (level > 0) {
		for (i = 0; i < level - 1; ++i) {
			if (branches & (1 << i)) {
				printf("│ ");
			} else {
				printf("  ");
			}
		}
		if (branches & (1 << i)) {
			printf("├ ");
		} else {
			printf("└ ");
		}
	}
	if (t == NULL) {
		printf("NULL\n");
	} else {
		printf("%i\n", t->key);
		if (t->left || t->right) {
			printTreeHelper(t->left, level + 1, branches | (1 << level));
			printTreeHelper(t->right, level + 1, branches);
		}
	}
}


void printTree(tree t) {
	printTreeHelper(t, 0, 0);
}