# Project Euler 126
# Least n such that C(n) = 1000 cuboid layer counts.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
function main() -> i32 {
let limit: i64 = 30000
let cnt: ptr<i32> = calloc(limit, 4)
if cnt == null { return 1 }
let mut a: i64 = 1
while 2 * (3 * a) < limit {
let mut b: i64 = 1
while b <= a && 2 * (a * b + a + b) < limit {
let mut c: i64 = 1
while c <= b {
let mut s: i64 = 2 * (a * b + b * c + c * a)
if s >= limit { break }
let mut inc: i64 = 4 * (a + b + c)
while s < limit {
cnt[s] = cnt[s] + 1
s = s + inc
inc = inc + 8
}
c = c + 1
}
b = b + 1
}
a = a + 1
}
let mut n: i64 = 1
while n < limit {
if cnt[n] == 1000 {
printf("%lld\n", n)
free(cnt)
return 0
}
n = n + 1
}
free(cnt)
return 1
}
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; }
int32_t main(void);
int32_t main(void) {
int64_t limit = 30000;
int32_t* cnt = (int32_t*)(calloc(limit, 4));
if (cnt == NULL) {
return 1;
}
int64_t a = 1;
while ((2 * (3 * a)) < limit) {
int64_t b = 1;
while ((b <= a && (2 * (((a * b) + a) + b)) < limit)) {
int64_t c = 1;
while (c <= b) {
int64_t s = (2 * (((a * b) + (b * c)) + (c * a)));
if (s >= limit) {
break;
}
int64_t inc = (4 * ((a + b) + c));
while (s < limit) {
cnt[s] = (cnt[s] + 1);
s = (s + inc);
inc = (inc + 8);
}
c = (c + 1);
}
b = (b + 1);
}
a = (a + 1);
}
int64_t n = 1;
while (n < limit) {
if (cnt[n] == 1000) {
printf("%lld\n", n);
free(cnt);
return 0;
}
n = (n + 1);
}
free(cnt);
return 1;
}