# Project Euler 240
# Dice top: 20d12, top 10 sum to 70.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
let mut NUM_DICE: i32 = 20
let mut MAX_POINTS: i32 = 12
let mut NUM_TOP: i32 = 10
let mut SUM_TOP: i32 = 70
let mut FACT: ptr<i64> = null
let mut DICES: ptr<i32> = null
function count_ways() -> i64 {
let how: ptr<i32> = calloc((MAX_POINTS + 1) as i64, 4)
let mut i: i32 = 0
while i < NUM_DICE {
how[DICES[i]] = how[DICES[i]] + 1
i = i + 1
}
let mut result: i64 = FACT[NUM_DICE]
i = 1
while i <= MAX_POINTS {
if how[i] > 1 {
result = result / FACT[how[i]]
}
i = i + 1
}
free(how)
return result
}
function search(len: i32) -> i64 {
if len == NUM_DICE {
return count_ways()
}
if len == NUM_TOP {
let mut s: i32 = 0
let mut i: i32 = 0
while i < NUM_TOP {
s = s + DICES[i]
i = i + 1
}
if s != SUM_TOP { return 0 }
}
let mut max_dice: i32 = MAX_POINTS
if len > 0 { max_dice = DICES[len - 1] }
let mut result: i64 = 0
let mut dice: i32 = 1
while dice <= max_dice {
DICES[len] = dice
result = result + search(len + 1)
dice = dice + 1
}
return result
}
function main() -> i32 {
FACT = calloc((NUM_DICE + 1) as i64, 8)
DICES = calloc(NUM_DICE as i64, 4)
if FACT == null || DICES == null { return 1 }
FACT[0] = 1
let mut i: i32 = 1
let mut cur: i64 = 1
while i <= NUM_DICE {
cur = cur * (i as i64)
FACT[i] = cur
i = i + 1
}
printf("%lld\n", search(0))
free(FACT); free(DICES)
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 count_ways(void);
int64_t search_i32(int32_t len);
int32_t main(void);
/* Module statics */
static int32_t NUM_DICE = 20;
static int32_t MAX_POINTS = 12;
static int32_t NUM_TOP = 10;
static int32_t SUM_TOP = 70;
static int64_t* FACT = NULL;
static int32_t* DICES = NULL;
int64_t count_ways(void) {
int32_t* how = (int32_t*)(calloc(((int64_t)((MAX_POINTS + 1))), 4));
int32_t i = 0;
while (i < NUM_DICE) {
how[DICES[i]] = (how[DICES[i]] + 1);
i = (i + 1);
}
int64_t result = FACT[NUM_DICE];
i = 1;
while (i <= MAX_POINTS) {
if (how[i] > 1) {
result = FLOW_CHECKED_DIV((result), (FACT[how[i]]));
}
i = (i + 1);
}
free(how);
return result;
}
int64_t search_i32(int32_t len) {
if (len == NUM_DICE) {
return count_ways();
}
if (len == NUM_TOP) {
int32_t s = 0;
int32_t i = 0;
while (i < NUM_TOP) {
s = (s + DICES[i]);
i = (i + 1);
}
if (s != SUM_TOP) {
return 0;
}
}
int32_t max_dice = MAX_POINTS;
if (len > 0) {
max_dice = DICES[(len - 1)];
}
int64_t result = 0;
int32_t dice = 1;
while (dice <= max_dice) {
DICES[len] = dice;
result = (result + search_i32((len + 1)));
dice = (dice + 1);
}
return result;
}
int32_t main(void) {
FACT = calloc(((int64_t)((NUM_DICE + 1))), 8);
DICES = calloc(((int64_t)(NUM_DICE)), 4);
if ((FACT == NULL || DICES == NULL)) {
return 1;
}
FACT[0] = 1;
int32_t i = 1;
int64_t cur = 1;
while (i <= NUM_DICE) {
cur = (cur * ((int64_t)(i)));
FACT[i] = cur;
i = (i + 1);
}
printf("%lld\n", search_i32(0));
free(FACT);
free(DICES);
return 0;
}