/* Define a check_heap function that can be called after malloc or
   free to check invariants of the heap structure for the allocator
   with coalescing. */

void check_heap()
{
  // Part 1:
  // Start at the first block payload
  // Traverse the list until we reach the terminator (0-sized allocated)
  // Make sure the footer size of each block matches the header size
  // If we detect an error, exit with status -1
  
  void *bp = first_bp;
  while (GET_SIZE(HDRP(bp)) != 0) {
    int Hsize = GET_SIZE(HDRP(bp));
    int Fsize = GET_SIZE(FTRP(bp));
    if (Hsize != Fsize) {
      exit(-1);
    }
    
    
    // Part 2:
    // In addition to the above, enforce the free list coalescing invariant
    // (No two consecutive blocks can be free)
    
    int isAlloc = GET_ALLOC(HDRP(bp));
    int isNextAlloc = GET_ALLOC(HDRP(NEXT_BLKP(bp)));
    if((isAlloc == isNextAlloc) && isAlloc == 0){
      exit(-1);
    }
    
     
    bp = NEXT_BLKP(bp);
  }

}