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Problem 618
Numbers with given prime factor sum: knapsack over primes to F_24. d[i] counts numbers whose prime factor sum is i, modulo 1e9. Sum d[F_k] for Fibonacci numbers F_k up to 46368.
View problem on Project Euler
Performance comparison
Metric Our solution Best known
Time complexity O(n^2)O(sqrt(n))
Space complexity O(n)O(1)
Approach Flow solution Trial division or Pollard rho
Verdict Suboptimal
Flow source
# Project Euler 618
# Numbers with given prime factor sum: knapsack over primes to F_24.
# d[i] counts numbers whose prime factor sum is i, modulo 1e9.
# Sum d[F_k] for Fibonacci numbers F_k up to 46368.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
const LIMIT: i64 = 46368
const MOD: i64 = 1000000000
function main() -> i32 {
let prime: ptr<i8> = calloc(LIMIT + 1, 1)
let d: ptr<i64> = calloc(LIMIT + 1, 8)
if prime == null || d == null {
return 1
}
let mut i: i64 = 0
while i <= LIMIT {
prime[i] = 1
i = i + 1
}
prime[0] = 0
prime[1] = 0
let mut j: i64 = 2
while j * j <= LIMIT {
if prime[j] == 1 {
let mut m: i64 = j * j
while m <= LIMIT {
prime[m] = 0
m = m + j
}
}
j = j + 1
}
d[0] = 1
let mut p: i64 = 2
while p <= LIMIT {
if prime[p] == 1 {
let mut idx: i64 = p
while idx <= LIMIT {
d[idx] = (d[idx] + p * d[idx - p]) % MOD
idx = idx + 1
}
}
p = p + 1
}
let mut total: i64 = 0
let mut a: i64 = 1
let mut b: i64 = 2
while b <= LIMIT {
total = (total + d[b]) % MOD
let c: i64 = a + b
a = b
b = c
}
free(prime as ptr<void>)
free(d as ptr<void>)
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; }
int32_t main(void);
static const int64_t LIMIT = 46368;
static const int64_t MOD = 1000000000;
int32_t main(void) {
int8_t* prime = (int8_t*)(calloc((LIMIT + 1), 1));
int64_t* d = (int64_t*)(calloc((LIMIT + 1), 8));
if ((prime == NULL || d == NULL)) {
return 1;
}
int64_t i = 0;
while (i <= LIMIT) {
prime[i] = 1;
i = (i + 1);
}
prime[0] = 0;
prime[1] = 0;
int64_t j = 2;
while ((j * j) <= LIMIT) {
if (prime[j] == 1) {
int64_t m = (j * j);
while (m <= LIMIT) {
prime[m] = 0;
m = (m + j);
}
}
j = (j + 1);
}
d[0] = 1;
int64_t p = 2;
while (p <= LIMIT) {
if (prime[p] == 1) {
int64_t idx = p;
while (idx <= LIMIT) {
d[idx] = FLOW_CHECKED_MOD(((d[idx] + (p * d[(idx - p)]))), (MOD));
idx = (idx + 1);
}
}
p = (p + 1);
}
int64_t total = 0;
int64_t a = 1;
int64_t b = 2;
while (b <= LIMIT) {
total = FLOW_CHECKED_MOD(((total + d[b])), (MOD));
int64_t c = (a + b);
a = b;
b = c;
}
free(((void*)(prime)));
free(((void*)(d)));
printf("%lld\n", total);
return 0;
}
Generated MLIR
module {
llvm.func @printf(!llvm.ptr, ...) -> i32
llvm.mlir.global internal constant @str_0("%lld\n\00") {addr_space = 0 : i32} : !llvm.array<6 x i8>
func.func private @calloc(i64, i64) -> !llvm.ptr
func.func private @free(!llvm.ptr) -> ()
// Constant: LIMIT
llvm.mlir.global internal constant @LIMIT(46368 : i64) : i64
// Constant: MOD
llvm.mlir.global internal constant @MOD(1000000000 : i64) : i64
func.func @main() -> i32 {
%1 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%2 = llvm.load %1 : !llvm.ptr -> i64
%3 = arith.constant 1 : i32
%5 = arith.extsi %3 : i32 to i64
%4 = arith.addi %2, %5 : i64
%6 = arith.constant 1 : i32
%7 = arith.extsi %6 : i32 to i64
%0 = func.call @calloc(%4, %7) : (i64, i64) -> !llvm.ptr
%9 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%10 = llvm.load %9 : !llvm.ptr -> i64
%11 = arith.constant 1 : i32
%13 = arith.extsi %11 : i32 to i64
%12 = arith.addi %10, %13 : i64
%14 = arith.constant 8 : i32
%15 = arith.extsi %14 : i32 to i64
%8 = func.call @calloc(%12, %15) : (i64, i64) -> !llvm.ptr
%16 = llvm.mlir.zero : !llvm.ptr
%17 = llvm.icmp "eq" %0, %16 : !llvm.ptr
%18 = scf.if %17 -> (i1) {
%19 = arith.constant true
scf.yield %19 : i1
} else {
%20 = llvm.mlir.zero : !llvm.ptr
%21 = llvm.icmp "eq" %8, %20 : !llvm.ptr
scf.yield %21 : i1
}
cf.cond_br %18, ^bb0, ^bb1
^bb0:
%22 = arith.constant 1 : i32
func.return %22 : i32
^bb1:
cf.br ^bb2
^bb2:
%23 = arith.constant 0 : i32
%24 = arith.extsi %23 : i32 to i64
%25 = llvm.mlir.constant(1 : i64) : i64
%26 = llvm.alloca %25 x i64 : (i64) -> !llvm.ptr
llvm.store %24, %26 : i64, !llvm.ptr
cf.br ^bb3
^bb3:
%27 = llvm.load %26 : !llvm.ptr -> i64
%28 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%29 = llvm.load %28 : !llvm.ptr -> i64
%30 = arith.cmpi sle, %27, %29 : i64
cf.cond_br %30, ^bb4, ^bb5
^bb4:
%31 = arith.constant 1 : i32
%32 = llvm.load %26 : !llvm.ptr -> i64
%33 = arith.trunci %31 : i32 to i8
%34 = llvm.getelementptr %0[%32] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %33, %34 : i8, !llvm.ptr
%35 = llvm.load %26 : !llvm.ptr -> i64
%36 = arith.constant 1 : i32
%38 = arith.extsi %36 : i32 to i64
%37 = arith.addi %35, %38 : i64
llvm.store %37, %26 : i64, !llvm.ptr
cf.br ^bb3
^bb5:
%39 = arith.constant 0 : i32
%40 = arith.constant 0 : i32
%41 = arith.trunci %39 : i32 to i8
%42 = arith.extsi %40 : i32 to i64
%43 = llvm.getelementptr %0[%42] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %41, %43 : i8, !llvm.ptr
%44 = arith.constant 0 : i32
%45 = arith.constant 1 : i32
%46 = arith.trunci %44 : i32 to i8
%47 = arith.extsi %45 : i32 to i64
%48 = llvm.getelementptr %0[%47] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %46, %48 : i8, !llvm.ptr
%49 = arith.constant 2 : i32
%50 = arith.extsi %49 : i32 to i64
%51 = llvm.mlir.constant(1 : i64) : i64
%52 = llvm.alloca %51 x i64 : (i64) -> !llvm.ptr
llvm.store %50, %52 : i64, !llvm.ptr
cf.br ^bb6
^bb6:
%53 = llvm.load %52 : !llvm.ptr -> i64
%54 = llvm.load %52 : !llvm.ptr -> i64
%55 = arith.muli %53, %54 : i64
%56 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%57 = llvm.load %56 : !llvm.ptr -> i64
%58 = arith.cmpi sle, %55, %57 : i64
cf.cond_br %58, ^bb7, ^bb8
^bb7:
%60 = llvm.load %52 : !llvm.ptr -> i64
%61 = llvm.getelementptr %0[%60] : (!llvm.ptr, i64) -> !llvm.ptr, i8
%59 = llvm.load %61 : !llvm.ptr -> i8
%62 = arith.constant 1 : i32
%64 = arith.extsi %59 : i8 to i32
%63 = arith.cmpi eq, %64, %62 : i32
cf.cond_br %63, ^bb9, ^bb10
^bb9:
%65 = llvm.load %52 : !llvm.ptr -> i64
%66 = llvm.load %52 : !llvm.ptr -> i64
%67 = arith.muli %65, %66 : i64
%68 = llvm.mlir.constant(1 : i64) : i64
%69 = llvm.alloca %68 x i64 : (i64) -> !llvm.ptr
llvm.store %67, %69 : i64, !llvm.ptr
cf.br ^bb12
^bb12:
%70 = llvm.load %69 : !llvm.ptr -> i64
%71 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%72 = llvm.load %71 : !llvm.ptr -> i64
%73 = arith.cmpi sle, %70, %72 : i64
cf.cond_br %73, ^bb13, ^bb14
^bb13:
%74 = arith.constant 0 : i32
%75 = llvm.load %69 : !llvm.ptr -> i64
%76 = arith.trunci %74 : i32 to i8
%77 = llvm.getelementptr %0[%75] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %76, %77 : i8, !llvm.ptr
%78 = llvm.load %69 : !llvm.ptr -> i64
%79 = llvm.load %52 : !llvm.ptr -> i64
%80 = arith.addi %78, %79 : i64
llvm.store %80, %69 : i64, !llvm.ptr
cf.br ^bb12
^bb14:
cf.br ^bb11
^bb10:
cf.br ^bb11
^bb11:
%81 = llvm.load %52 : !llvm.ptr -> i64
%82 = arith.constant 1 : i32
%84 = arith.extsi %82 : i32 to i64
%83 = arith.addi %81, %84 : i64
llvm.store %83, %52 : i64, !llvm.ptr
cf.br ^bb6
^bb8:
%85 = arith.constant 1 : i32
%86 = arith.constant 0 : i32
%87 = arith.extsi %85 : i32 to i64
%88 = arith.extsi %86 : i32 to i64
%89 = llvm.getelementptr %8[%88] : (!llvm.ptr, i64) -> !llvm.ptr, i64
llvm.store %87, %89 : i64, !llvm.ptr
%90 = arith.constant 2 : i32
%91 = arith.extsi %90 : i32 to i64
%92 = llvm.mlir.constant(1 : i64) : i64
%93 = llvm.alloca %92 x i64 : (i64) -> !llvm.ptr
llvm.store %91, %93 : i64, !llvm.ptr
cf.br ^bb15
^bb15:
%94 = llvm.load %93 : !llvm.ptr -> i64
%95 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%96 = llvm.load %95 : !llvm.ptr -> i64
%97 = arith.cmpi sle, %94, %96 : i64
cf.cond_br %97, ^bb16, ^bb17
^bb16:
%99 = llvm.load %93 : !llvm.ptr -> i64
%100 = llvm.getelementptr %0[%99] : (!llvm.ptr, i64) -> !llvm.ptr, i8
%98 = llvm.load %100 : !llvm.ptr -> i8
%101 = arith.constant 1 : i32
%103 = arith.extsi %98 : i8 to i32
%102 = arith.cmpi eq, %103, %101 : i32
cf.cond_br %102, ^bb18, ^bb19
^bb18:
%104 = llvm.load %93 : !llvm.ptr -> i64
%105 = llvm.mlir.constant(1 : i64) : i64
%106 = llvm.alloca %105 x i64 : (i64) -> !llvm.ptr
llvm.store %104, %106 : i64, !llvm.ptr
cf.br ^bb21
^bb21:
%107 = llvm.load %106 : !llvm.ptr -> i64
%108 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%109 = llvm.load %108 : !llvm.ptr -> i64
%110 = arith.cmpi sle, %107, %109 : i64
cf.cond_br %110, ^bb22, ^bb23
^bb22:
%112 = llvm.load %106 : !llvm.ptr -> i64
%113 = llvm.getelementptr %8[%112] : (!llvm.ptr, i64) -> !llvm.ptr, i64
%111 = llvm.load %113 : !llvm.ptr -> i64
%114 = llvm.load %93 : !llvm.ptr -> i64
%116 = llvm.load %106 : !llvm.ptr -> i64
%117 = llvm.load %93 : !llvm.ptr -> i64
%118 = arith.subi %116, %117 : i64
%119 = llvm.getelementptr %8[%118] : (!llvm.ptr, i64) -> !llvm.ptr, i64
%115 = llvm.load %119 : !llvm.ptr -> i64
%120 = arith.muli %114, %115 : i64
%121 = arith.addi %111, %120 : i64
%122 = llvm.mlir.addressof @MOD : !llvm.ptr
%123 = llvm.load %122 : !llvm.ptr -> i64
%124 = arith.remsi %121, %123 : i64
%125 = llvm.load %106 : !llvm.ptr -> i64
%126 = llvm.getelementptr %8[%125] : (!llvm.ptr, i64) -> !llvm.ptr, i64
llvm.store %124, %126 : i64, !llvm.ptr
%127 = llvm.load %106 : !llvm.ptr -> i64
%128 = arith.constant 1 : i32
%130 = arith.extsi %128 : i32 to i64
%129 = arith.addi %127, %130 : i64
llvm.store %129, %106 : i64, !llvm.ptr
cf.br ^bb21
^bb23:
cf.br ^bb20
^bb19:
cf.br ^bb20
^bb20:
%131 = llvm.load %93 : !llvm.ptr -> i64
%132 = arith.constant 1 : i32
%134 = arith.extsi %132 : i32 to i64
%133 = arith.addi %131, %134 : i64
llvm.store %133, %93 : i64, !llvm.ptr
cf.br ^bb15
^bb17:
%135 = arith.constant 0 : i32
%136 = arith.extsi %135 : i32 to i64
%137 = llvm.mlir.constant(1 : i64) : i64
%138 = llvm.alloca %137 x i64 : (i64) -> !llvm.ptr
llvm.store %136, %138 : i64, !llvm.ptr
%139 = arith.constant 1 : i32
%140 = arith.extsi %139 : i32 to i64
%141 = llvm.mlir.constant(1 : i64) : i64
%142 = llvm.alloca %141 x i64 : (i64) -> !llvm.ptr
llvm.store %140, %142 : i64, !llvm.ptr
%143 = arith.constant 2 : i32
%144 = arith.extsi %143 : i32 to i64
%145 = llvm.mlir.constant(1 : i64) : i64
%146 = llvm.alloca %145 x i64 : (i64) -> !llvm.ptr
llvm.store %144, %146 : i64, !llvm.ptr
cf.br ^bb24
^bb24:
%147 = llvm.load %146 : !llvm.ptr -> i64
%148 = llvm.mlir.addressof @LIMIT : !llvm.ptr
%149 = llvm.load %148 : !llvm.ptr -> i64
%150 = arith.cmpi sle, %147, %149 : i64
cf.cond_br %150, ^bb25, ^bb26
^bb25:
%151 = llvm.load %138 : !llvm.ptr -> i64
%153 = llvm.load %146 : !llvm.ptr -> i64
%154 = llvm.getelementptr %8[%153] : (!llvm.ptr, i64) -> !llvm.ptr, i64
%152 = llvm.load %154 : !llvm.ptr -> i64
%155 = arith.addi %151, %152 : i64
%156 = llvm.mlir.addressof @MOD : !llvm.ptr
%157 = llvm.load %156 : !llvm.ptr -> i64
%158 = arith.remsi %155, %157 : i64
llvm.store %158, %138 : i64, !llvm.ptr
%159 = llvm.load %142 : !llvm.ptr -> i64
%160 = llvm.load %146 : !llvm.ptr -> i64
%161 = arith.addi %159, %160 : i64
%162 = llvm.load %146 : !llvm.ptr -> i64
llvm.store %162, %142 : i64, !llvm.ptr
llvm.store %161, %146 : i64, !llvm.ptr
cf.br ^bb24
^bb26:
func.call @free(%0) : (!llvm.ptr) -> ()
func.call @free(%8) : (!llvm.ptr) -> ()
%165 = llvm.mlir.addressof @str_0 : !llvm.ptr
%166 = llvm.load %138 : !llvm.ptr -> i64
%167 = llvm.call @printf(%165, %166) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr, i64) -> i32
%168 = arith.constant 0 : i32
func.return %168 : i32
}
}