# Project Euler 043
# Sum of 0–9 pandigital numbers with substring divisibility properties.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
function swap(a: ptr<i32>, i: i32, j: i32) -> void {
let t: i32 = a[i]
a[i] = a[j]
a[j] = t
}
function next_perm(a: ptr<i32>, n: i32) -> bool {
let mut i: i32 = n - 2
while i >= 0 && a[i] >= a[i + 1] { i = i - 1 }
if i < 0 { return false }
let mut j: i32 = n - 1
while a[j] <= a[i] { j = j - 1 }
swap(a, i, j)
let mut l: i32 = i + 1
let mut r: i32 = n - 1
while l < r {
swap(a, l, r)
l = l + 1
r = r - 1
}
return true
}
function sub3(a: ptr<i32>, i: i32) -> i32 {
return a[i] * 100 + a[i + 1] * 10 + a[i + 2]
}
function to_num(a: ptr<i32>) -> i64 {
let mut v: i64 = 0
for i in 0..10 {
v = v * 10 + (a[i] as i64)
}
return v
}
function main() -> i32 {
let d: ptr<i32> = calloc(10, 4)
if d == null { return 1 }
for i in 0..10 {
d[i] = i
}
let primes: array<i32, 7> = [2, 3, 5, 7, 11, 13, 17]
let mut total: i64 = 0
while true {
let mut ok: bool = true
let mut k: i32 = 0
while k < 7 {
if sub3(d, k + 1) % primes[k] != 0 {
ok = false
break
}
k = k + 1
}
if ok {
total = total + to_num(d)
}
if !next_perm(d, 10) { break }
}
printf("%lld\n", total)
free(d)
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; }
void swap_ptr_i32_i32_i32(int32_t* a, int32_t i, int32_t j);
bool next_perm_ptr_i32_i32(int32_t* a, int32_t n);
int32_t sub3_ptr_i32_i32(int32_t* a, int32_t i);
int64_t to_num_ptr_i32(int32_t* a);
int32_t main(void);
void swap_ptr_i32_i32_i32(int32_t* a, int32_t i, int32_t j) {
int32_t t = a[i];
a[i] = a[j];
a[j] = t;
}
bool next_perm_ptr_i32_i32(int32_t* a, int32_t n) {
int32_t i = (n - 2);
while ((i >= 0 && a[i] >= a[(i + 1)])) {
i = (i - 1);
}
if (i < 0) {
return 0;
}
int32_t j = (n - 1);
while (a[j] <= a[i]) {
j = (j - 1);
}
swap_ptr_i32_i32_i32(a, i, j);
int32_t l = (i + 1);
int32_t r = (n - 1);
while (l < r) {
swap_ptr_i32_i32_i32(a, l, r);
l = (l + 1);
r = (r - 1);
}
return 1;
}
int32_t sub3_ptr_i32_i32(int32_t* a, int32_t i) {
return (((a[i] * 100) + (a[(i + 1)] * 10)) + a[(i + 2)]);
}
int64_t to_num_ptr_i32(int32_t* a) {
int64_t v = 0;
int32_t __flow_step_1 = 1;
for (int32_t i = 0; (0 <= 10) ? i < 10 : i > 10; i += (0 <= 10) ? 1 : -1) {
v = ((v * 10) + ((int64_t)(a[i])));
}
return v;
}
int32_t main(void) {
int32_t* d = (int32_t*)(calloc(10, 4));
if (d == NULL) {
return 1;
}
int32_t __flow_step_2 = 1;
for (int32_t i = 0; (0 <= 10) ? i < 10 : i > 10; i += (0 <= 10) ? 1 : -1) {
d[i] = i;
}
int32_t primes[7] = { 2, 3, 5, 7, 11, 13, 17 };
int64_t total = 0;
while (1) {
bool ok = 1;
int32_t k = 0;
while (k < 7) {
if (FLOW_CHECKED_MOD((sub3_ptr_i32_i32(d, (k + 1))), ((((unsigned)(k) < 7) ? primes[k] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(k), 7), flow_fault_handler("array index out of bounds"), primes[0])))) != 0) {
ok = 0;
break;
}
k = (k + 1);
}
if (ok) {
total = (total + to_num_ptr_i32(d));
}
if ((!(next_perm_ptr_i32_i32(d, 10)))) {
break;
}
}
printf("%lld\n", total);
free(d);
return 0;
}