/*
Tori Fujinami
min priority queue implemented as a heap for astar open and closed set usage
sorts based on totalDist
use an array for node storage (preferably resizeable one?-->max size for astar for robot cars = row*col)
header file 
*/

#ifndef PQUEUE_H_
#define PQUEUE_H_

typedef struct node
{
	int row;
	int col;
	int distTravelFromStart;
	int distToGoal;
	int totalDist;
	int pushOrder;		//order that element was pushed onto the heap
} node_t;

typedef struct dictElem
{
	int parentRow;
	int parentCol;
	int heapIdx;
	char heapId;
} dictElem_t;

typedef struct heap
{
	int numElems;	//initially no elements on the array
	node_t elems[400];	//array of size 400, max number of elements for ge 423 robot contest that can be on a heap
} heap_t;

void startHeap(heap_t* pq);	//use for initialization so that declared heap has no elements
int size(heap_t pq);
node_t peek(heap_t pq);		//so that can look at top of heap without removing
void push(node_t newElem, heap_t* pq, dictElem_t nodeTrack[], int mapSize);		//pushes element onto the heap
void pop(heap_t* pq, dictElem_t nodeTrack[], int mapSize);

//pQueue helper functions:
int root();		//returns the index of the root of the heap
int leftChild(int idx);		//returns the index of the left child of a node in the heap
int rightChild(int idx);	//returns the index of the right child of a node in the heap
int parent(int idx);		//returns the index of the parent child of a node in the heap
int hasChild(int idx, heap_t pq);		//returns 1 if the node at this index has at least one child, 0 if there are no children
int maxPriorityChild(int idx, heap_t pq);	//returns the index of the right priority child

#endif