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

void fill(char des[20][40], int x, int y, char c)
{
/* check if we are in bounds */

        if (x < 0) return;
        if (x > 19) return;
        if (y < 0) return;
        if (y > 39) return;
/* if current position is a space, fill it in with <char> */

        if(des[x][y]==' ') des[x][y]=c;

/* recursively check around the current position for more white space to fill, until we reach non-space chars all around */

        if(des[x][y-1]==' ') fill(des,x,y-1,c);
        if(des[x-1][y]==' ') fill(des,x-1,y,c);
        if(des[x][y+1]==' ') fill(des,x,y+1,c);
        if(des[x+1][y]==' ') fill(des,x+1,y,c);
}

int main(void)
{
        int line,column,i,j;
        char charsel;
        char drawing[20][40];
        FILE *filein=NULL,*fileout=NULL;

/* open files */

        filein=fopen("in","rt");
        fileout=fopen("out","wt");

/* read the array from file ( array represents and ascii drawing of a house basically */

        for(i=0;i<20;i++)
        {
                for(j=0;j<40;j++)
                fscanf(filein,"%c",&drawing[i][j]);
        }
/* read coordinate at which we want to start filling in */

        printf("Insert line (0-19) and column (0-39) number for the start position\n");
        scanf("%d", &line);
        scanf("%d", &column);
        getchar();

/* read character we are filling in with */

        printf("Insert the fill character (must not be an empty space)\n");
        scanf("%c",&charsel);

/* run recursive function */

        fill(drawing,line,column,charsel);

/* print array back to output file */

        for(i=0;i<20;i++)
        {
                for(j=0;j<40;j++)
                fprintf(fileout, "%c", drawing[i][j]);
        };
        printf("Result has been spewed to file named 'out'");
/* close shit up */
        fclose(filein);
        fclose(fileout);

        getchar();
        return 0;
}