Advent_of_code_2015/2015_day_3/day_3.c

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
FILE *fptr;

typedef struct housearray {
  int **houses;
  int rows·in·array;
  int columns·in·array;
  int number·of·houses;
  int x·coord;
  int y·coord;
  int x_coord_origin;
  int y_coord_origin;
  int seq·no;
} Housearray;

//initial array allocation
Housearray *inithousearray(void){
  Housearray* f = (Housearray*)malloc(sizeof(Housearray));
  if (f == NULL) return NULL;

  f->rows·in·array =1;
  f->columns·in·array = 1;
  f->x_coord_origin = 0;
  f->y_coord_origin =0;
  f->number·of·houses = 0;
  f->x·coord = 0;
  f->y·coord = 0;
  f->seq·no = 0;

  f->houses = (int**)malloc(f->rows·in·array * sizeof(int*));//allocating the rows
  if (f->houses == NULL) {
    free(f);
    return NULL; //handling if there isn't enough memory to allocate or allocation fails
  }
  f->houses[0] = (int*)malloc(f->columns·in·array * sizeof(int));
  if (f->houses[0] == NULL){
    free(f->houses);
    free(f);
    return NULL;
  }
  f->houses[0][0] = 1;//santa has been to the starting point
  return f;
}




//void move·santa(Housearray *f, char dir){
//  //check if array is empty
//  int p2x·coord, p2y·coord = 0;
//  if (  f->number·of·houses == 0) {
//    f->number·of·houses = 9;//initialise length 9
//    f->rows·in·array = f->columns·in·array = 3;//initialise a 3x3 map
//    f->x·coord = f->y·coord = 2;//Initialise to 2,2
//  else if (dir == "V"){
//    p2y·coord = f->y·coord -1;
//    if (p2y·coord ==0){
//
//    }
//  }
//
//}

//void get·seq·no(int xcoord, int ycoord, int nocolumns, int norows, int numberofhouses){
//  //transforms coordinates into a sequence number
//  //https://stackoverflow.com/questions/2151084/map-a-2d-array-onto-a-1d-array
//  //Think I might need to reexamine indexing
//}
void movenorth(Housearray* f, char direction){
  int old_rows = f->rows·in·array;
  int old_cols = f-> columns·in·array;
  //update y coordinate
  f->y·coord--;
  //check if expansion needed
  if (f->y·coord - f->y_coord_origin < 0){
    //Expand north
    int new_rows = old_rows +1;
    int new_cols = old_cols;
    //creates an array of pointers to point to my rows of integers
    int** new_grid = (int**)malloc(new_rows * sizeof(int*));
    if (new_grid == NULL){
      return;
    }
    for (int i = 0; i< old_rows; ++i){
      new_grid[i+1] = f->houses[i];//repeat without the plus one for the southward add row
    }
    new_grid[0] = (int*)calloc(new_cols, sizeof(int));//Initialising the new row to empty
    free(f->houses);
    f->houses = new_grid;
    f->rows·in·array = new_rows;
    f->columns·in·array = new_cols;
    f->y_coord_origin--;
  }
  //updating the visit count
  int grid_x = f->x·coord - f->x_coord_origin;
  int grid_y = f->y·coord - f->y_coord_origin;
  f->houses[grid_y][grid_x]++;
  //comment
}

void movesouth(Housearray* f, char direction){
  int old_rows = f->rows·in·array;
  int old_cols = f-> columns·in·array;
  //update y coordinate
  f->y·coord++;
  //check if expansion needed
  if (f->y·coord - f->y_coord_origin >= f->rows·in·array){
    //Expand south
    int new_rows = old_rows +1;
    int new_cols = old_cols;
    //creates an array of pointers to point to my rows of integers
    int** new_grid = (int**)malloc(new_rows * sizeof(int*));
    for (int i = 0; i< old_rows; ++i){
      new_grid[i] = f->houses[i];
    }
    new_grid[new_rows - 1] = (int*)calloc(new_cols, sizeof(int));//Initialising the new row to empty
    free(f->houses);
    f->houses = new_grid;
    f->rows·in·array = new_rows;
    f->columns·in·array = new_cols;

  }
  //updating the visit count
  int grid_x = f->x·coord - f->x_coord_origin;
  int grid_y = f->y·coord - f->y_coord_origin;
  f->houses[grid_y][grid_x]++;
}


int main(){
  Housearray* my_house_array = inithousearray();
  if (my_house_array == NULL){
    fprintf(stderr, "ERROR:initialisation of struct failed\n");
    return 1;
  }
//  char c;
  char up = '^';
  char down = 'v';
  char left = '<';
  char right = '>';

  char ch;
  fptr = fopen("2015_day_3_input.txt", "r");  
  if(fptr == NULL) {
    printf("Not able to open the file.");
    return 1;
  }
  //https://www.geeksforgeeks.org/c-program-to-read-contents-of-whole-file/
  while ((ch = fgetc(fptr)) != EOF) {
      printf("%c", ch);
      if (ch == up){
        printf("\nUP");
        movenorth(my_house_array, ch);
      }else if (ch == down){
        printf("\nDOWN");
        movesouth(my_house_array, ch);        
      }
      printf("\n%d ycoordinate\n",my_house_array->y·coord);
      printf("\n%d rows in array\n",my_house_array->rows·in·array);


}


}