#ifndef COLOR_H
#define COLOR_H
#include <stdio.h>

/**
* Given n by m matrix (array[n][m]) finds adjacent entries with
* the same color to replace it.
* params:
*     n - number of rows in matrix
*     m - number of columns in matrix
*     arr - matrix to paint
*     i - row for current entry being processed
*     j - column for current entry being processed
*     ol - old color to find in matrix and replace
*     nw - new color to replace old color
*     touched - array to check if current entry was already processed
**/
int _paint
(int n, int m, int *arr, int i, int j, int ol, int nw, int *touched)
{
  int curind = n * i + j;		//index of current entry

  if(i < 0 || i > n || j < 0 || j > n) {//index out of bounds
    return 1;
  }

  if(arr[curind] != ol || touched[curind]) {
    return 1;
  }

  touched[curind] = 1;
  arr[curind] = nw;
  return
    _paint(n, m, arr, i, j + 1, ol, nw, touched) &&
    _paint(n, m, arr, i, j - 1, ol, nw, touched) &&
    _paint(n, m, arr, i + 1, j, ol, nw, touched) &&
    _paint(n, m, arr, i - 1, j, ol, nw, touched) &&
    _paint(n, m, arr, i - 1, j - 1, ol, nw, touched) &&
    _paint(n, m, arr, i - 1, j + 1, ol, nw, touched) &&
    _paint(n, m, arr, i + 1, j - 1, ol, nw, touched) &&
    _paint(n, m, arr, i + 1, j + 1, ol, nw, touched);

}

int paint_bucket_fill
(int n, int m, int *arr, int i, int j, int new_color)
{
  int ind, touched[n * m];

  if(i < 0 || i > n || j < 0 || j > m) {
    fputs("invalid i j values.\n", stderr);
    return -1;
  }

  for(ind = 0; ind < (n * m); ++ind) {
    touched[ind] = 0;
  }

  int old_color = arr[n * i + j];
  return _paint(n, m, arr, i, j, old_color, new_color, touched);
}

#endif /* color.h */