static char help[] = "Tests PetscHeapCreate()\n\n";

#include <petscsys.h>
#include <petscviewer.h>

int main(int argc, char **args)
{
  PetscHeap h;
  PetscInt  id, val, cnt, *values;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &args, NULL, help));
  PetscCall(PetscHeapCreate(9, &h));
  PetscCall(PetscHeapAdd(h, 0, 100));
  PetscCall(PetscHeapAdd(h, 1, 19));
  PetscCall(PetscHeapAdd(h, 2, 36));
  PetscCall(PetscHeapAdd(h, 3, 17));
  PetscCall(PetscHeapAdd(h, 4, 3));
  PetscCall(PetscHeapAdd(h, 5, 25));
  PetscCall(PetscHeapAdd(h, 6, 1));
  PetscCall(PetscHeapAdd(h, 8, 2));
  PetscCall(PetscHeapAdd(h, 9, 7));
  PetscCall(PetscPrintf(PETSC_COMM_SELF, "Initial heap:\n"));
  PetscCall(PetscHeapView(h, NULL));

  PetscCall(PetscHeapPop(h, &id, &val));
  PetscCall(PetscHeapStash(h, id, val + 10));
  PetscCall(PetscHeapPop(h, &id, &val));
  PetscCall(PetscHeapStash(h, id, val + 10));
  PetscCall(PetscPrintf(PETSC_COMM_SELF, "Pop two items, increment, and place in stash:\n"));
  PetscCall(PetscHeapView(h, NULL));

  PetscCall(PetscHeapUnstash(h));
  PetscCall(PetscPrintf(PETSC_COMM_SELF, "After unpacking the stash:\n"));
  PetscCall(PetscHeapView(h, NULL));

  PetscCall(PetscMalloc1(9, &values));
  PetscCall(PetscHeapPop(h, &id, &val));
  cnt = 0;
  while (id >= 0) {
    values[cnt++] = val;
    PetscCall(PetscHeapPop(h, &id, &val));
  }
  PetscCall(PetscPrintf(PETSC_COMM_SELF, "Sorted values:\n"));
  PetscCall(PetscIntView(cnt, values, PETSC_VIEWER_STDOUT_SELF));
  PetscCall(PetscFree(values));
  PetscCall(PetscHeapDestroy(&h));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:

TEST*/