#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>

char input[] =
{
#embed "input.txt"
,'\0' // null terminator
,'\0'
};

int width = 0;
int height = 0;

uint64_t power(uint64_t base, uint64_t exp) {
    uint64_t i, result = 1;
    for (i = 0; i < exp; i++)
        result *= base;
    return result;
}


void print_field(uint8_t* surrounds){
    for(int x = 0; x < height; x++){
        for(int y = 0; y < width; y++){
            if((surrounds[(x)*(width+2)+(y)]&0x80) == 0x80){
                printf("%d", surrounds[(x)*(width+2)+(y)]-0x80);
            }else{
                //printf("%c", input[(x)*(width+1)+(y)]);
                printf(".");
            }
        }
        printf("\n");
    }
    printf("==============================================\n");
}

int main(int argc, char *argv[]){
    clock_t start, end;
    start = clock();

    while(input[width] != '\n'){
        width++;
    }
    //printf("width: %d\n", width);
    
    while(input[height*(width+1)+1] != 0){
        height++;
    }
    //printf("height: %d\n", height);
    

    uint8_t* surrounds = calloc((height+2)*(width+2), sizeof(uint8_t))+width+1;

    for(int x = 0; x < height; x++){
        for(int y = 0; y< width; y++){
            if(input[(x)*(width+1)+(y)] == '@'){
                    surrounds[(x-1)*(width+2)+(y-1)]    += 1;
                    surrounds[(x-1)*(width+2)+(y)]      += 1;
                    surrounds[(x-1)*(width+2)+(y+1)]    += 1;
                    surrounds[(x)*(width+2)+(y-1)]      += 1;
                    surrounds[(x)*(width+2)+(y)]        += 0x80;
                    surrounds[(x)*(width+2)+(y+1)]      += 1;
                    surrounds[(x+1)*(width+2)+(y-1)]    += 1;
                    surrounds[(x+1)*(width+2)+(y)]      += 1;
                    surrounds[(x+1)*(width+2)+(y+1)]    += 1;
            }
            //if(surrounds[(x)*width+(y)] < 8 && input[(x)*(width+1)+(y)] == '@'){
            //    printf("%d", surrounds[(x)*(width+2)+(y)]);
            //}else{
            //    printf("%c", input[(x)*(width+1)+(y)]);
            //}
        }
        //printf("\n");
    }
    //print_field(surrounds);
    
    uint64_t count = 0;
    uint64_t count_2 = 0;
    bool cont = true;
    int* removes = calloc((height)*(width)*2, sizeof(int));

    while (cont){
        count_2 = 0;
        for(int x = 0; x < height; x++){
            for(int y = 0; y < width; y++){
                if((surrounds[(x)*(width+2)+(y)]&0x7f) < 4 && (surrounds[(x)*(width+2)+(y)]&0x80) == 0x80){
                    
                    removes[count_2*2] = x;
                    removes[count_2*2+1] = y;
                    count_2++;
                    //printf("removing %d, %d\n", x, y);
                    //input[(x)*(width+1)+(y)] = 'x';
                    //printf("%d", surrounds[(x)*width+(y)]);
                }//if((surrounds[(x)*(width+2)+(y)]&0x7f) > 8 && (surrounds[(x)*(width+2)+(y)]&0x80) == 0x80){
                    //printf("underflow detechted, aborting\n");
                    //cont = false;
                //}
            }
            //printf("\n");
        }
        //print_field(surrounds);
        count += count_2;
        
        //printf("count = %lu\n========\n", count);
        if(count_2 == 0){
            cont = false;
        }
        //printf("cont: %s\n", cont ? "true" : "false");
        //printf("count_2 = %lu\n", count_2);
        //printf("count = %lu\n", count);


        for(int i = 0; i < count_2; i++){
            int x = removes[i*2];
            int y = removes[i*2+1];
            surrounds[(x-1)*(width+2)+(y-1)]    -= 1;
            surrounds[(x-1)*(width+2)+(y)]      -= 1;
            surrounds[(x-1)*(width+2)+(y+1)]    -= 1;
            surrounds[(x)*(width+2)+(y-1)]      -= 1;
            surrounds[(x)*(width+2)+(y)]        -= 0x80;
            surrounds[(x)*(width+2)+(y+1)]      -= 1;
            surrounds[(x+1)*(width+2)+(y-1)]    -= 1;
            surrounds[(x+1)*(width+2)+(y)]      -= 1;
            surrounds[(x+1)*(width+2)+(y+1)]    -= 1;
        }
        //print_field(surrounds);
        //sleep(1);
    }

    //free(removes);
    //free(surrounds-width-1);

    end = clock();
    printf("count: %lu\n", count);
    clock_t ticks_taken = end - start; 
    double time_taken = ((double)ticks_taken)/CLOCKS_PER_SEC;
    printf("time take: %f ticks\n", time_taken);
    printf("CLOCKS_PER_SEC: %ld\n", CLOCKS_PER_SEC);


    exit(1);
}