#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>


int get_acces(int** matrix,int i,int j,int last_i,int last_j) { // last_{i,j} are bools to indicate we are in the last row}
    int neighbors = -1;
    int i_0 = 0;
    int i_last = 0;
    int j_0= 0;
    int j_last = 0;

    if (i == 0) {
i_0 = 1;
    } else if (last_i) {

i_last = 1;
    }
    if (j==0) {

j_0 = 1;
    } else if (last_j) {

j_last = 1;
    }

    // for step 2 we will be working modulus 2. during the run, once we establish a roll as accesible it will get replaces with 3.
    // while counting it for the neighbors it will still result in true for %2.
    // once a run is over, we iterate over the whole matrix again and reduce all 3's by 1.
    for (int ii = -1+i_0; ii<=1-i_last; ii++) {
        for (int jj = -1+j_0; jj<=1-j_last ; jj++) {
            if (matrix[i+ii][j+jj]%2) {
                neighbors++;
            }
        }
    }
    if (neighbors<4) {
        return 1;
    } else {
        return 0;
    }
}

int main(int argc, char* argv[]) {


    FILE* f = NULL;
    char* line = NULL;
    size_t size = 0;
    ssize_t nread = 0;
    int len = 0;
    int w = 0;
    int access = 0;
    int accesible_rolls = 0;
    int total_accesible_rolls = 0;

    int** matrix_ptr = NULL;


    f = fopen(argv[1], "r");


    while ((nread = getline(&line, &size, f)) != -1) {
        w = nread-2;
        matrix_ptr = (int **)realloc(matrix_ptr, (len+1) * (nread-2)*sizeof(int));
        matrix_ptr[len] = (int *)malloc((nread-2)*sizeof(int));
        for (int i = 0; i< nread-1; i++) {
            if (line[i] == '@') {
                matrix_ptr[len][i] = 1;

            } else {
                matrix_ptr[len][i] = 0;
            }
            //               printf("%d",(&matrix_ptr)[j][i]);
        }
        len++;
    }

    // just a matrix out of input.

    //
    //  [(i-1,j-1)][(i-1,j)] [(i-1,j+1)]
    //  [(i,j-1)]  [(i,j)]   [(i,j+1)]
    //  [(i+1,j-1)][(i+1,j)] [(i+1,j+1)]
    //  check all of those in clockwise order
    // 

    do {
accesible_rolls=0;
    for (int i = 0; i<len; i++) {
        for (int j = 0; j<w+1; j++) {
            if(matrix_ptr[i][j]==1) {
            access = get_acces(matrix_ptr, i, j, (i==len-1), (j==w));
                if (access) {
                    matrix_ptr[i][j]+=2;
                    accesible_rolls++;
                printf("x");
                }else {

                printf("@");
                }
            } else {
            printf(".");
            }

        }
        printf("\n");
    }


    for (int i = 0; i<len; i++) {
        for (int j = 0; j<w+1; j++) {
            if(matrix_ptr[i][j]==3) {
                matrix_ptr[i][j]--;

        }
    }}

    printf("\n\n accesible rolls: %d\n",accesible_rolls);
    total_accesible_rolls+=accesible_rolls;
    }while (accesible_rolls>0);

    



    printf("\n\n  total accesible rolls: %d\n",total_accesible_rolls);


    free(matrix_ptr);
    free(f);
    free(line);
    return 0;
}