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

int saved[255];

int it_collatz(int n, int counter) {
    if (n == 1) {
        return counter;
    } else if (n == 2) {
        return counter + 1;
    }
    switch (n % 4) {
        case 0:
            return it_collatz(n / 4, counter + 2);
        case 3:
            return it_collatz(n * 2 + (n / 4) + 2, counter + 4);
        default:
            return it_collatz(n - (n / 4), counter + 3);
    }
}

int collatz(int n) {
    if (saved[n] == 0) saved[n] = it_collatz(n, 0);
    return saved[n];
}

typedef struct {
    int n;
    int counter;
} data;

int greater(const void *a, const void *b) {
    return (*(data*)b).counter - (*(data*)a).counter;
}

int main() {
    data d[255];
    long begin, end;
    begin = clock();
    for (int i = 1; i < 256; i++) {
        d[i-1].n = i;
        d[i-1].counter = collatz(i);
    }
    qsort(d, 255, sizeof(data), greater);
    for (int i = 0; i < 16; i++) {
        printf("%x %x\n", d[i].n, d[i].counter);
    }
    end = clock();
    printf("%ld\n", end - begin);
    return 0;
}