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

long long seed;

long long middle_square_math(){
        seed = seed * seed / 1000 % 1000000;
        return seed;
}

long long middle_square_string() {
    char squared_seed_str[13];   // Store the seed as a string with space for null terminator
    char result_str[7];  // Store the result as a string with space for null terminator
    long long result;

    int mid = 3; // Middle index for 6-digit seed (could be generalized to n/2)
    long long squared_seed = seed * seed; // Square the seed

    // Convert the squared seed to a string with 12 characters
    sprintf(squared_seed_str, "%012lld", squared_seed);
    //printf("String of squared seed (%012lld)=%s\n\n",seed, squared_seed_str);

    //strncpy(result_str, squared_seed_str + mid, mid*2);
    for(int i=0; i<=mid*2; i++)
        result_str[i] = squared_seed_str[i+mid];

    result_str[6] = '\0'; // Null-terminate the result string
    //printf("Middle from squared seed %s\n\n", result_str);

    // Convert the middle digits back to a long long integer
    result = atoll(result_str);
    //printf("%lld\n", result);
    seed = result;
    return seed;
}

int main(){

        seed = 675248;
        printf("Middle Square Method (math)\n");
        for(int i=1;i<=5;i++)
            printf("%lld\n", middle_square_math());

        // Reset the seed
        seed = 675248;
        printf("\n\nMiddle Square Method (string)\n");
        for(int i=1;i<=5;i++)
            printf("%lld\n", middle_square_string());
        return 0;
}