# Project Euler 622
# Riffle shuffles: sum of deck sizes with order dividing 60 exactly.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
function modpow(base0: i64, exp0: i64, mod: i64) -> i64 {
let mut r: i64 = 1
let mut b: i64 = base0 % mod
let mut e: i64 = exp0
while e > 0 {
if (e & 1) == 1 {
let t: i128 = (r as i128) * (b as i128) % (mod as i128)
r = t as i64
}
let t2: i128 = (b as i128) * (b as i128) % (mod as i128)
b = t2 as i64
e = e / 2
}
return r
}
function main() -> i32 {
let target: i64 = (1 as i64 << 60) - 1
# factor target and enumerate divisors
let pf: ptr<i64> = calloc(64, 8)
let pe: ptr<i64> = calloc(64, 8)
let mut pn: i64 = 0
let mut n: i64 = target
let mut p: i64 = 2
while p * p <= n {
if n % p == 0 {
let mut e: i64 = 0
while n % p == 0 {
n = n / p
e = e + 1
}
pf[pn] = p
pe[pn] = e
pn = pn + 1
}
if p == 2 { p = 3 } else { p = p + 2 }
}
if n > 1 {
pf[pn] = n
pe[pn] = 1
pn = pn + 1
}
# generate all divisors
let mut dcount: i64 = 1
let mut i: i64 = 0
while i < pn {
dcount = dcount * (pe[i] + 1)
i = i + 1
}
let divs: ptr<i64> = calloc(dcount, 8)
let mut nd: i64 = 1
divs[0] = 1
i = 0
while i < pn {
let prime: i64 = pf[i]
let exp: i64 = pe[i]
let prev: i64 = nd
let mut e: i64 = 1
let mut pp: i64 = prime
while e <= exp {
let mut j: i64 = 0
while j < prev {
divs[nd] = divs[j] * pp
nd = nd + 1
j = j + 1
}
pp = pp * prime
e = e + 1
}
i = i + 1
}
# order primes of 60
let op: ptr<i64> = calloc(8, 8)
let mut on: i64 = 0
let mut oo: i64 = 60
p = 2
while p * p <= oo {
if oo % p == 0 {
op[on] = p
on = on + 1
while oo % p == 0 { oo = oo / p }
}
if p == 2 { p = 3 } else { p = p + 2 }
}
if oo > 1 {
op[on] = oo
on = on + 1
}
let mut total: i64 = 0
i = 0
while i < nd {
let d: i64 = divs[i]
if d > 1 {
let mut ok: i32 = 1
let mut t: i64 = 0
while t < on {
if modpow(2, 60 / op[t], d) == 1 {
ok = 0
break
}
t = t + 1
}
if ok == 1 {
total = total + d + 1
}
}
i = i + 1
}
free(pf)
free(pe)
free(divs)
free(op)
printf("%lld\n", total)
return 0
}
Generated C
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Flow runtime helpers */
typedef struct flow_temp_node { struct flow_temp_node* next; } flow_temp_node;
static flow_temp_node* flow_temp_head = NULL;
static int flow_temp_atexit_set = 0;
__attribute__((unused)) static void flow_temp_free_all(void) {
while (flow_temp_head) {
flow_temp_node* n = flow_temp_head;
flow_temp_head = n->next;
free(n);
}
}
__attribute__((unused)) static void* flow_temp_alloc(size_t nbytes) {
flow_temp_node* node = (flow_temp_node*)malloc(sizeof(flow_temp_node) + nbytes);
if (!node) return NULL;
node->next = flow_temp_head;
flow_temp_head = node;
if (!flow_temp_atexit_set) {
flow_temp_atexit_set = 1;
atexit(flow_temp_free_all);
}
return (void*)(node + 1);
}
#ifndef FLOW_DIAG
#define FLOW_DIAG(msg) fprintf(stderr, "%s", (msg))
#endif
#ifndef FLOW_LOG
#define FLOW_LOG(fmt, ...) printf(fmt, __VA_ARGS__)
#endif
#ifndef FLOW_LOG_EMPTY
#define FLOW_LOG_EMPTY(fmt) printf(fmt)
#endif
static char* flow_strcat(const char* a, const char* b) {
size_t la = strlen(a ? a : ""), lb = strlen(b ? b : "");
char* r = (char*)flow_temp_alloc(la + lb + 1);
if (!r) return NULL;
if (la) memcpy(r, a, la);
if (lb) memcpy(r + la, b, lb);
r[la + lb] = '\0';
return r;
}
#define __flow_in_arr(arr, val) __extension__ ({ \
int _found = 0; \
size_t _n = sizeof(arr)/sizeof((arr)[0]); \
for (size_t _i = 0; _i < _n; _i++) { \
if ((arr)[_i] == (val)) { _found = 1; break; } \
} _found; })
/* Unified fault handler (MISRA #279) — override with -DFLOW_FAULT_HANDLER=fn */
#ifndef FLOW_FAULT_HANDLER
__attribute__((unused)) static inline void flow_fault_handler(const char* msg) {
fprintf(stderr, "flow: %s\n", msg ? msg : "fault");
abort();
#if defined(__GNUC__) || defined(__clang__)
__builtin_unreachable();
#endif
}
#else
#define flow_fault_handler FLOW_FAULT_HANDLER
#endif
#define flow_div_by_zero_handler() flow_fault_handler("division by zero")
#define flow_shift_ub_handler() flow_fault_handler("invalid shift (amount out of range or left-shift of negative)")
#ifndef FLOW_CHECKED_DIV
#define FLOW_CHECKED_DIV(L, R) (((R) != 0) ? ((L) / (R)) : (flow_div_by_zero_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_MOD
#define FLOW_CHECKED_MOD(L, R) (((R) != 0) ? ((L) % (R)) : (flow_div_by_zero_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_SHL
#define FLOW_CHECKED_SHL(L, R) ((((R) >= 0) && ((unsigned long long)(R) < (sizeof(L) * 8ull)) && ((L) >= 0)) ? ((L) << (R)) : (flow_shift_ub_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_SHR
#define FLOW_CHECKED_SHR(L, R) ((((R) >= 0) && ((unsigned long long)(R) < (sizeof(L) * 8ull))) ? ((L) >> (R)) : (flow_shift_ub_handler(), (L) * 0))
#endif
#include <math.h>
void* _ui_state = NULL;
static inline float i32_to_f32(int32_t v) { return (float)v; }
/* Host stub for @gpu kernels (device codegen replaces this). */
static inline int32_t gpu_thread_id(void) { return 0; }
int64_t modpow_i64_i64_i64(int64_t base0, int64_t exp0, int64_t mod);
int32_t main(void);
int64_t modpow_i64_i64_i64(int64_t base0, int64_t exp0, int64_t mod) {
int64_t r = 1;
int64_t b = FLOW_CHECKED_MOD((base0), (mod));
int64_t e = exp0;
while (e > 0) {
if ((e & 1) == 1) {
__int128 t = FLOW_CHECKED_MOD(((((__int128)(r)) * ((__int128)(b)))), (((__int128)(mod))));
r = ((int64_t)(t));
}
__int128 t2 = FLOW_CHECKED_MOD(((((__int128)(b)) * ((__int128)(b)))), (((__int128)(mod))));
b = ((int64_t)(t2));
e = FLOW_CHECKED_DIV((e), (2));
}
return r;
}
int32_t main(void) {
int64_t target = (FLOW_CHECKED_SHL((((int64_t)(1))), (60)) - 1);
int64_t* pf = (int64_t*)(calloc(64, 8));
int64_t* pe = (int64_t*)(calloc(64, 8));
int64_t pn = 0;
int64_t n = target;
int64_t p = 2;
while ((p * p) <= n) {
if (FLOW_CHECKED_MOD((n), (p)) == 0) {
int64_t e = 0;
while (FLOW_CHECKED_MOD((n), (p)) == 0) {
n = FLOW_CHECKED_DIV((n), (p));
e = (e + 1);
}
pf[pn] = p;
pe[pn] = e;
pn = (pn + 1);
}
if (p == 2) {
p = 3;
} else {
p = (p + 2);
}
}
if (n > 1) {
pf[pn] = n;
pe[pn] = 1;
pn = (pn + 1);
}
int64_t dcount = 1;
int64_t i = 0;
while (i < pn) {
dcount = (dcount * (pe[i] + 1));
i = (i + 1);
}
int64_t* divs = (int64_t*)(calloc(dcount, 8));
int64_t nd = 1;
divs[0] = 1;
i = 0;
while (i < pn) {
int64_t prime = pf[i];
int64_t exp = pe[i];
int64_t prev = nd;
int64_t e = 1;
int64_t pp = prime;
while (e <= exp) {
int64_t j = 0;
while (j < prev) {
divs[nd] = (divs[j] * pp);
nd = (nd + 1);
j = (j + 1);
}
pp = (pp * prime);
e = (e + 1);
}
i = (i + 1);
}
int64_t* op = (int64_t*)(calloc(8, 8));
int64_t on = 0;
int64_t oo = 60;
p = 2;
while ((p * p) <= oo) {
if (FLOW_CHECKED_MOD((oo), (p)) == 0) {
op[on] = p;
on = (on + 1);
while (FLOW_CHECKED_MOD((oo), (p)) == 0) {
oo = FLOW_CHECKED_DIV((oo), (p));
}
}
if (p == 2) {
p = 3;
} else {
p = (p + 2);
}
}
if (oo > 1) {
op[on] = oo;
on = (on + 1);
}
int64_t total = 0;
i = 0;
while (i < nd) {
int64_t d = divs[i];
if (d > 1) {
int32_t ok = 1;
int64_t t = 0;
while (t < on) {
if (modpow_i64_i64_i64(2, FLOW_CHECKED_DIV((60), (op[t])), d) == 1) {
ok = 0;
break;
}
t = (t + 1);
}
if (ok == 1) {
total = ((total + d) + 1);
}
}
i = (i + 1);
}
free(pf);
free(pe);
free(divs);
free(op);
printf("%lld\n", total);
return 0;
}