/***** 65535 *****/

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

int main()
{
    unsigned i, r, poly, count;
    FILE *file;

    file = fopen("p65535", "w");
    if (file == NULL) return 1;
    printf("List of polynomials with period 65535\n");
    fprintf(file, "List of polynomials with period 65535\n");
    count = 0;  poly = 0x8000U;
    do {
        i = 0;  r = 1;
        do {
            if (r & 1) r = (r >> 1) ^ poly;
            else       r >>= 1;
            i++;
        } while (r != 1);
        if (i == 65535U) {
            printf(" %04X", poly);
            fprintf(file, " %04X", poly);
            if (++count % 10 == 0) {
                printf("\n");
                fprintf(file, "\n");
            }
        }
    } while (poly++ != 0xFFFFU);
    printf("\n%u polynomials\n", count);
    fprintf(file, "\n%u polynomials\n", count);
    fclose(file);
    return EXIT_SUCCESS;
}

/***** 32767 *****/

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

int main()
{
    unsigned i, r, poly, count;
    static unsigned a[4096];
    FILE *file;

    file = fopen("p32767", "w");
    if (file == NULL) return 1;
    printf("List of polynomials with period 32767\n");
    fprintf(file, "List of polynomials with period 32767\n");
    count = 0;  poly = 0x8000U;
    do {
        for (i = 0; i < 4096; i++) a[i] = 0;
        i = 0;  r = 1;
        do {
            if (r & 1) r = (r >> 1) ^ poly;
            else       r >>= 1;
            i++;
            a[r >> 4] |= 1U << (r & 15);
        } while (r != 1);
        if (i != 32767U) continue;
        i = 0;  r = 3;
        do {
            if (r & 1) r = (r >> 1) ^ poly;
            else       r >>= 1;
            i++;
            if (a[r >> 4] & (1U << (r & 15))) break;
        } while (r != 3);
        if (i != 32767U) continue;
        printf(" %04X", poly);
        fprintf(file, " %04X", poly);
        if (++count % 10 == 0) {
            printf("\n");
            fprintf(file, "\n");
        }
    } while (poly++ != 0xFFFFU);
    printf("\n%u polynomials\n", count);
    fprintf(file, "\n%u polynomials\n", count);
    fclose(file);
    return EXIT_SUCCESS;
}