# Project Euler 109
# How many distinct ways to checkout with a score less than 100?
function main() -> i32 {
# singles 1..20,25; doubles 2..40,50; triples 3..60
let mut values: array<i32, 62>
let mut types: array<i32, 62> # 1=S,2=D,3=T
let mut n: i32 = 0
let mut i: i32 = 1
while i <= 20 {
values[n] = i
types[n] = 1
n = n + 1
values[n] = 2 * i
types[n] = 2
n = n + 1
values[n] = 3 * i
types[n] = 3
n = n + 1
i = i + 1
}
values[n] = 25
types[n] = 1
n = n + 1
values[n] = 50
types[n] = 2
n = n + 1
let mut count: i64 = 0
# checkout ends with a double
let mut d: i32 = 0
while d < n {
if types[d] != 2 {
d = d + 1
continue
}
let checkout: i32 = values[d]
if checkout < 100 {
count = count + 1 # just the double
}
# one dart then double
let mut a: i32 = 0
while a < n {
let s: i32 = values[a] + checkout
if s < 100 {
count = count + 1
}
a = a + 1
}
# two darts then double — unordered for first two (a <= b by index to avoid perm)
a = 0
while a < n {
let mut b: i32 = a
while b < n {
let s2: i32 = values[a] + values[b] + checkout
if s2 < 100 {
count = count + 1
}
b = b + 1
}
a = a + 1
}
d = d + 1
}
printf("%lld\n", count)
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; }
int32_t main(void);
int32_t main(void) {
int32_t values[62];
int32_t types[62];
int32_t n = 0;
int32_t i = 1;
while (i <= 20) {
values[n] = i;
types[n] = 1;
n = (n + 1);
values[n] = (2 * i);
types[n] = 2;
n = (n + 1);
values[n] = (3 * i);
types[n] = 3;
n = (n + 1);
i = (i + 1);
}
values[n] = 25;
types[n] = 1;
n = (n + 1);
values[n] = 50;
types[n] = 2;
n = (n + 1);
int64_t count = 0;
int32_t d = 0;
while (d < n) {
if ((((unsigned)(d) < 62) ? types[d] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(d), 62), flow_fault_handler("array index out of bounds"), types[0])) != 2) {
d = (d + 1);
continue;
}
int32_t checkout = (((unsigned)(d) < 62) ? values[d] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(d), 62), flow_fault_handler("array index out of bounds"), values[0]));
if (checkout < 100) {
count = (count + 1);
}
int32_t a = 0;
while (a < n) {
int32_t s = ((((unsigned)(a) < 62) ? values[a] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(a), 62), flow_fault_handler("array index out of bounds"), values[0])) + checkout);
if (s < 100) {
count = (count + 1);
}
a = (a + 1);
}
a = 0;
while (a < n) {
int32_t b = a;
while (b < n) {
int32_t s2 = (((((unsigned)(a) < 62) ? values[a] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(a), 62), flow_fault_handler("array index out of bounds"), values[0])) + (((unsigned)(b) < 62) ? values[b] : (fprintf(stderr, "array index %d out of bounds (size %d)\n", (int)(b), 62), flow_fault_handler("array index out of bounds"), values[0]))) + checkout);
if (s2 < 100) {
count = (count + 1);
}
b = (b + 1);
}
a = (a + 1);
}
d = (d + 1);
}
printf("%lld\n", count);
return 0;
}