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

#define N 16

static int done = 0;

static void end(int sig)
{
    done = 1;
}

int main(int argc, char **argv)
{
    time_t seed = time(NULL);
    if (argv[1]) {
        seed = atoi(argv[1]);
    }
    srand(seed);

    // Set the handler so we finish cleanly
    signal(SIGINT, end);

    int width = 0;
    {
        int c = N;
        while (c) {
            width++;
            c /= 10;
        }
    }

    // Print initial layout
    for (int i = 0; i < N; i++) {
        printf("%*d: 0\n", width, i);
    }

    unsigned long hits[N] = {};
    unsigned long n = 0;
    while (!done) {
        n++;
        printf("\r\e[%dA", N);

        hits[rand() % N]++;
        for (int i = 0; i < N; i++) {
            printf("%*d: %f\n", width, i, (double)hits[i] / n);
        }
        printf("Iterations: %lu", n);
    }

    // Print one last time for cleanliness
    printf("\r\e[%dA", N);
    for (int i = 0; i < N; i++) {
        printf("%*d: %f\n", width, i, (double)hits[i] / n);
    }
    printf("Iterations: %lu\n", n);
}