int main(int argc, char *argv[]) {
  // timer
  struct timeval start, end;
  long mtime, seconds, useconds;    
  gettimeofday(&start, NULL);

  time_t startTime = time(0);

  if (argc != 3) {
    printf("wrong number of inputs\n");
    exit(1);
  }

  int** grid = fileTo2dArray(argv[1], atoi(argv[2]));
  Puzzle* p = new Puzzle(grid, atoi(argv[2]));
  p->initialize();

  /*  
  p->printGridDim();
  p->printGrid();
  p->printPreassigned();
  p->printInitCandidates();
  
  printf("start: %i, %i\n", p->getCurrentRow(), p->getCurrentCol());
  while (p->nextSlot()) {
    printf("nextslot: row is %i, col is %i\n", p->getCurrentRow(), p->getCurrentCol());
  }
  
  while (p->prevSlot()) {
    printf("prevslot: row is %i, col is %i\n", p->getCurrentRow(), p->getCurrentCol());
  }
  

  printf("TEST: check candidates\n");
  p->checkCandidates(p->getCurrentRow(), p->getCurrentCol());
  printf("TEST: assign\n");
  p->assign(p->getCurrentRow(), p->getCurrentCol());
  printf("TEST: update neighbors\n");
  p->updateNeighborConflicts(p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(0, 0), true);
  printf("TEST: check neighbors\n");
  p->checkNeighborCandidates(p->getCurrentRow(), p->getCurrentCol());
  */

  //int counter=10000;  
  while (!p->isSolved()) {
  //while (!p->isSolved() && counter>0) {
    //counter--;
    //printf("step 1\n");
    // step 1
    if (checkCurrentCandidates(p)) {
      //printf("step 3\n");
      // step 3
      bool succeeded = assignAndValidate(p);
      if (succeeded) {
        //printf("step 5\n");
        // step 5
        advanceSlot(p);
      }
      else {
        //printf("step 4\n");
        // step 4
        backtrack(p);
      }
    }
    else {
      //printf("step 2\n");
      // step 2
      if (reverseSlot(p)) {
        //printf("step 4\n");
        // step 4
        backtrack(p);
      }
      else {
        //printf("step 2 failed\n");
        break;
      }
    }
  }
  
  if (p->isSolved()) {
    printf("solution found!\n");
    p->printGrid();
  }
  else {
    printf("no solution found\n");
  }
  
  
  //printf("deinitializing\n");
  p->deinitialize();
  //printf("deinitialized\n");
  delete2dIntArray(grid, atoi(argv[2]));
  //printf("deleted original array.\n");

  //timer
  double seconds_since_start = difftime( time(0), startTime);
  printf("%f seconds to run program\n", seconds_since_start);

  gettimeofday(&end, NULL);
  seconds  = end.tv_sec  - start.tv_sec;
  useconds = end.tv_usec - start.tv_usec;
  mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5;
  printf("Elapsed time: %ld milliseconds\n", mtime);
}
int main(int argc, char *argv[]) {
  // timer
  struct timeval start, end;
  long mtime, seconds, useconds;    
  gettimeofday(&start, NULL);

  time_t startTime = time(0);

  if (argc != 3) {
    printf("wrong number of inputs\n");
    exit(1);
  }

  int** grid = fileTo2dArray(argv[1], atoi(argv[2]));

  Puzzle* p = new Puzzle(grid, atoi(argv[2]));
  p->initialize();

  int dim = atoi(argv[2]);

  if (dim<16) parallelStartDepth=86;

  int highestVisitedPosition = 0;
  int currentDepth = 0;
  int numTried = 0;
  std::vector<Puzzle*> toSolve;
  Puzzle* solved = NULL;

  while (!p->isSolved()) {

    if (testLevel > 1 && highestVisitedPosition < p->positionOnVisited) {
      if (testLevel > 1) printf("highestVisitedPosition is now %i\n", p->positionOnVisited);
      highestVisitedPosition = p->positionOnVisited;
    }
    // step 1
    if (currentDepth >= parallelStartDepth && checkCurrentCandidates(p)) {
      Puzzle* forSolving = p->makePreassignedCopy();

      if (testLevel > 1) {
        printf("making copy: old candidates are\n");
        p->printInitCandidates();
        printf("new candidates are\n");
        forSolving->printInitCandidates();
      }
      toSolve.push_back(forSolving);

      if (testLevel > 1) printf("toSolve size: %i\n", (int)toSolve.size());

      if (reverseSlot(p)) {
        currentDepth--;
        backtrack(p);
      }
      else {
        break;
      }

      if (toSolve.size() >= vectorSizeLimit) {
        if (testLevel > 1) printf("toSolve reached %i elements, attempting solve now\n", vectorSizeLimit);
        solved = solveInitializedPuzzles(&toSolve, highestVisitedPosition, &numTried);
        if (solved != NULL) {
          break;
        }
        else while (toSolve.size() > 0) {
          toSolve.pop_back();
        }
      }
    }
    else if (checkCurrentCandidates(p)) {
      // step 3
      bool succeeded = assignAndValidate(p);
      if (succeeded) {
        // step 5
        advanceSlot(p);
        currentDepth++;
      }
      else {
        // step 4
        backtrack(p);
      }
    }
    else {
      // step 2
      if (reverseSlot(p)) {
        currentDepth--;
        // step 4
        backtrack(p);
      }
      else {
        //printf("step 2 failed\n");
        break;
      }
    }
  }

  if (!p->isSolved()) {
    p->deinitialize();
    delete p;

    if (testLevel > 1) printf("number of branches: %i\n", (int)toSolve.size());

    if (solved == NULL) {
      solved = solveInitializedPuzzles(&toSolve, highestVisitedPosition, &numTried);
    }

    if (testLevel > 1) printf("parallel start depth was %i\n", parallelStartDepth);
  }
  else {
    solved = p;
    printf("puzzle solved while creating parallel branches, no parallelism done\n");
  }
  
  if (solved != NULL && solved->isSolved()) {
    printf("solution found!\n");
    solved->printGrid();
  }
  else {
    printf("no solution found\n");
  }

  solved->deinitialize();
  delete solved;

  //timer
  double seconds_since_start = difftime( time(0), startTime);
  printf("%f seconds to run program\n", seconds_since_start);

  gettimeofday(&end, NULL);
  seconds  = end.tv_sec  - start.tv_sec;
  useconds = end.tv_usec - start.tv_usec;
  mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5;
  printf("Elapsed time: %ld milliseconds\n", mtime);
}
int main(int argc, char *argv[]) {
  // timer
  struct timeval start, end;
  long mtime, seconds, useconds;    
  gettimeofday(&start, NULL);

  time_t startTime = time(0);

  if (argc != 3) {
    printf("wrong number of inputs\n");
    exit(1);
  }

  int** grid = fileTo2dArray(argv[1], atoi(argv[2]));
  Puzzle p = Puzzle(grid, atoi(argv[2]));
  p.initialize();

  /*  
  p->printGridDim();
  p->printGrid();
  p->printPreassigned();
  p->printInitCandidates();
  
  printf("start: %i, %i\n", p->getCurrentRow(), p->getCurrentCol());
  while (p->nextSlot()) {
    printf("nextslot: row is %i, col is %i\n", p->getCurrentRow(), p->getCurrentCol());
  }
  
  while (p->prevSlot()) {
    printf("prevslot: row is %i, col is %i\n", p->getCurrentRow(), p->getCurrentCol());
  }
  

  printf("TEST: check candidates\n");
  p->checkCandidates(p->getCurrentRow(), p->getCurrentCol());
  printf("TEST: assign\n");
  p->assign(p->getCurrentRow(), p->getCurrentCol());
  printf("TEST: update neighbors\n");
  p->updateNeighborConflicts(p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(0, 0), true);
  printf("TEST: check neighbors\n");
  p->checkNeighborCandidates(p->getCurrentRow(), p->getCurrentCol());
  */

  //int counter=10000;  
  while (!p.isSolved()) {
  //while (!p->isSolved() && counter>0) {
    //counter--;
    if (testLevel > 0) printf("step 1: on (%i, %i)\n", p.getCurrentRow(), p.getCurrentCol());
    //printf("step 1: current row %i, current col %i, %i\n", p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(p->getCurrentRow(), p->getCurrentCol()));
    bool hasCandidate = p.checkCandidates(p.getCurrentRow(), p.getCurrentCol(), false);
    //printf("step 1\n");
    // step 1
    if (hasCandidate) {
      //printf("step 3\n");
      // step 3
      bool succeeded;
      if (p.assign(p.getCurrentRow(), p.getCurrentCol())) {
        if (testLevel > 0) 
          printf("step 3: on (%i, %i), assigned %i\n", p.getCurrentRow(), p.getCurrentCol(), p.getCurrentAssigned(p.getCurrentRow(), p.getCurrentCol()));
        //printf("step 3: assignment succeeded\n");
        //printf("calling updateNeighborConflicts with %i, %i, %i\n", p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(p->getCurrentRow(), p->getCurrentCol()));
        //printf("pre-assign candidate list: \n"); 
        //p->printInitCandidates();
        // deprecated
        //p->updateNeighborConflicts(p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(p->getCurrentRow(), p->getCurrentCol()), true);
        //printf("post-assign candidate list: \n"); 
        //p->printInitCandidates();    
        //printf("step 3: updateNeighborConflicts succeeded\n");
        succeeded = p.checkNeighborAssignments(p.getCurrentRow(), p.getCurrentCol());
      }
      else {
        printf("error: reached slot with no candidates. shouldn't happen. exiting.\n");
        exit(1);
      }

      if (succeeded) {
        //printf("step 5\n");
        // step 5
        if (testLevel > 0) printf("step 5: next slot\n");
        p.nextSlot();
        p.copyCandidates(p.getCurrentRow(), p.getCurrentCol());
      }
      else {
        //printf("step 4\n");
        // step 4
        if (testLevel > 0) 
          printf("step 4: on (%i, %i), unassigning %i\n", p.getCurrentRow(), p.getCurrentCol(), p.getCurrentAssigned(p.getCurrentRow(), p.getCurrentCol()));
        //printf("pre-update candidate list: \n"); 
        //p.printInitCandidates();
        //deprecated
        //p->updateNeighborConflicts(p->getCurrentRow(), p->getCurrentCol(), p->getCurrentAssigned(p->getCurrentRow(), p->getCurrentCol()), false);
        //printf("post-update candidate list: \n"); 
        //p->printInitCandidates();
        p.removeAndInvalidate(p.getCurrentRow(), p.getCurrentCol());
        // loops back to front
      }
    }
    else {
      //printf("step 2\n");
      // step 2
      if (testLevel > 0) printf("step 2: reversing slot\n");
      p.resetCandidates(p.getCurrentRow(), p.getCurrentCol());
      bool reversedSlot = p.prevSlot();

      if (reversedSlot) {
        //printf("step 4\n");
        // step 4
        if (testLevel > 0) 
          printf("step 4: on (%i, %i), unassigning %i\n", p.getCurrentRow(), p.getCurrentCol(), p.getCurrentAssigned(p.getCurrentRow(), p.getCurrentCol()));
        //printf("pre-update candidate list: \n"); 
        //p.printInitCandidates();
        //deprecated
        //p.updateNeighborConflicts(p.getCurrentRow(), p.getCurrentCol(), p.getCurrentAssigned(p.getCurrentRow(), p.getCurrentCol()), false);
        //printf("post-update candidate list: \n"); 
        //p.printInitCandidates();
        p.removeAndInvalidate(p.getCurrentRow(), p.getCurrentCol());
        // loops back to front
      }
      else {
        //printf("step 2 failed\n");
        break;
      }
    }
  }
  
  if (p.isSolved()) {
    printf("solution found!\n");
    p.printGrid();
  }
  else {
    printf("no solution found\n");
  }
  
  
  //printf("deinitializing\n");
  p.deinitialize();
  //printf("deinitialized\n");
  delete2dIntArray(grid, atoi(argv[2]));
  //printf("deleted original array.\n");

  //timer
  double seconds_since_start = difftime( time(0), startTime);
  printf("%f seconds to run program\n", seconds_since_start);

  gettimeofday(&end, NULL);
  seconds  = end.tv_sec  - start.tv_sec;
  useconds = end.tv_usec - start.tv_usec;
  mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5;
  printf("Elapsed time: %ld milliseconds\n", mtime);
}