← All problems
Problem 429
Sum of squares of unitary divisors of 10^8!, mod 10^9+9.
View problem on Project Euler
Performance comparison
Metric Our solution Best known
Time complexity O(n^2)O(n log log n)
Space complexity O(n)O(n)
Approach Flow solution Sieve-based divisor sums
Verdict Suboptimal
Flow source
# Project Euler 429
# Sum of squares of unitary divisors of 10^8!, mod 10^9+9.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
}
function modpow(base0: i64, exp0: i64, mod: i64) -> i64 {
let mut r: i64 = 1
let mut b: i64 = base0 % mod
let mut e: i64 = exp0
while e > 0 {
if e % 2 == 1 {
r = ((r as i128) * (b as i128) % (mod as i128)) as i64
}
b = ((b as i128) * (b as i128) % (mod as i128)) as i64
e = e / 2
}
return r
}
function count_factors(n: i64, p: i64) -> i64 {
let mut c: i64 = 0
let mut pp: i64 = p
while pp <= n {
c = c + n / pp
if pp > n / p { break }
pp = pp * p
}
return c
}
function main() -> i32 {
let LIMIT: i64 = 100000000
let MOD: i64 = 1000000009
let half: i64 = (LIMIT >> 1) + 1
let sieve: ptr<i8> = calloc(half, 1)
if sieve == null { return 1 }
sieve[0] = 1
let mut i: i64 = 1
while 2 * i * i < half {
if sieve[i] == 0 {
let mut current: i64 = 3 * i + 1
let step: i64 = 2 * i + 1
while current < half {
sieve[current] = 1
current = current + step
}
}
i = i + 1
}
let mut ans: i64 = 1
let c2: i64 = count_factors(LIMIT, 2)
ans = (ans * (1 + modpow(2, 2 * c2, MOD))) % MOD
let mut p: i64 = 3
while p <= LIMIT {
if sieve[p >> 1] == 0 {
let c: i64 = count_factors(LIMIT, p)
ans = (ans * (1 + modpow(p, 2 * c, MOD))) % MOD
}
p = p + 2
}
printf("%lld\n", ans)
free(sieve)
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 modpow_i64_i64_i64(int64_t base0, int64_t exp0, int64_t mod);
int64_t count_factors_i64_i64(int64_t n, int64_t p);
int32_t main(void);
int64_t modpow_i64_i64_i64(int64_t base0, int64_t exp0, int64_t mod) {
int64_t r = 1;
int64_t b = FLOW_CHECKED_MOD((base0), (mod));
int64_t e = exp0;
while (e > 0) {
if (FLOW_CHECKED_MOD((e), (2)) == 1) {
r = ((int64_t)(FLOW_CHECKED_MOD(((((__int128)(r)) * ((__int128)(b)))), (((__int128)(mod))))));
}
b = ((int64_t)(FLOW_CHECKED_MOD(((((__int128)(b)) * ((__int128)(b)))), (((__int128)(mod))))));
e = FLOW_CHECKED_DIV((e), (2));
}
return r;
}
int64_t count_factors_i64_i64(int64_t n, int64_t p) {
int64_t c = 0;
int64_t pp = p;
while (pp <= n) {
c = (c + FLOW_CHECKED_DIV((n), (pp)));
if (pp > FLOW_CHECKED_DIV((n), (p))) {
break;
}
pp = (pp * p);
}
return c;
}
int32_t main(void) {
int64_t LIMIT = 100000000;
int64_t MOD = 1000000009;
int64_t half = (FLOW_CHECKED_SHR((LIMIT), (1)) + 1);
int8_t* sieve = (int8_t*)(calloc(half, 1));
if (sieve == NULL) {
return 1;
}
sieve[0] = 1;
int64_t i = 1;
while (((2 * i) * i) < half) {
if (sieve[i] == 0) {
int64_t current = ((3 * i) + 1);
int64_t step = ((2 * i) + 1);
while (current < half) {
sieve[current] = 1;
current = (current + step);
}
}
i = (i + 1);
}
int64_t ans = 1;
int64_t c2 = count_factors_i64_i64(LIMIT, 2);
ans = FLOW_CHECKED_MOD(((ans * (1 + modpow_i64_i64_i64(2, (2 * c2), MOD)))), (MOD));
int64_t p = 3;
while (p <= LIMIT) {
if (sieve[FLOW_CHECKED_SHR((p), (1))] == 0) {
int64_t c = count_factors_i64_i64(LIMIT, p);
ans = FLOW_CHECKED_MOD(((ans * (1 + modpow_i64_i64_i64(p, (2 * c), MOD)))), (MOD));
}
p = (p + 2);
}
printf("%lld\n", ans);
free(sieve);
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) -> ()
func.func @modpow(%arg0: i64, %arg1: i64, %arg2: i64) -> i64 {
%0 = arith.constant 1 : i32
%1 = arith.extsi %0 : i32 to i64
%2 = llvm.mlir.constant(1 : i64) : i64
%3 = llvm.alloca %2 x i64 : (i64) -> !llvm.ptr
llvm.store %1, %3 : i64, !llvm.ptr
%4 = arith.remsi %arg0, %arg2 : i64
%5 = llvm.mlir.constant(1 : i64) : i64
%6 = llvm.alloca %5 x i64 : (i64) -> !llvm.ptr
llvm.store %4, %6 : i64, !llvm.ptr
%7 = llvm.mlir.constant(1 : i64) : i64
%8 = llvm.alloca %7 x i64 : (i64) -> !llvm.ptr
llvm.store %arg1, %8 : i64, !llvm.ptr
cf.br ^bb0
^bb0:
%9 = llvm.load %8 : !llvm.ptr -> i64
%10 = arith.constant 0 : i32
%12 = arith.extsi %10 : i32 to i64
%11 = arith.cmpi sgt, %9, %12 : i64
cf.cond_br %11, ^bb1, ^bb2
^bb1:
%13 = llvm.load %8 : !llvm.ptr -> i64
%14 = arith.constant 2 : i32
%16 = arith.extsi %14 : i32 to i64
%15 = arith.remsi %13, %16 : i64
%17 = arith.constant 1 : i32
%19 = arith.extsi %17 : i32 to i64
%18 = arith.cmpi eq, %15, %19 : i64
cf.cond_br %18, ^bb3, ^bb4
^bb3:
%20 = llvm.load %3 : !llvm.ptr -> i64
%21 = arith.extsi %20 : i64 to i128
%22 = llvm.load %6 : !llvm.ptr -> i64
%23 = arith.extsi %22 : i64 to i128
%25 = arith.trunci %21 : i128 to i64
%26 = arith.trunci %23 : i128 to i64
%24 = arith.muli %25, %26 : i64
%27 = arith.extsi %arg2 : i64 to i128
%29 = arith.trunci %27 : i128 to i64
%28 = arith.remsi %24, %29 : i64
llvm.store %28, %3 : i64, !llvm.ptr
cf.br ^bb5
^bb4:
cf.br ^bb5
^bb5:
%30 = llvm.load %6 : !llvm.ptr -> i64
%31 = arith.extsi %30 : i64 to i128
%32 = llvm.load %6 : !llvm.ptr -> i64
%33 = arith.extsi %32 : i64 to i128
%35 = arith.trunci %31 : i128 to i64
%36 = arith.trunci %33 : i128 to i64
%34 = arith.muli %35, %36 : i64
%37 = arith.extsi %arg2 : i64 to i128
%39 = arith.trunci %37 : i128 to i64
%38 = arith.remsi %34, %39 : i64
llvm.store %38, %6 : i64, !llvm.ptr
%40 = llvm.load %8 : !llvm.ptr -> i64
%41 = arith.constant 2 : i32
%43 = arith.extsi %41 : i32 to i64
%42 = arith.divsi %40, %43 : i64
llvm.store %42, %8 : i64, !llvm.ptr
cf.br ^bb0
^bb2:
%44 = llvm.load %3 : !llvm.ptr -> i64
func.return %44 : i64
}
func.func @count_factors(%arg0: i64, %arg1: i64) -> i64 {
%45 = arith.constant 0 : i32
%46 = arith.extsi %45 : i32 to i64
%47 = llvm.mlir.constant(1 : i64) : i64
%48 = llvm.alloca %47 x i64 : (i64) -> !llvm.ptr
llvm.store %46, %48 : i64, !llvm.ptr
%49 = llvm.mlir.constant(1 : i64) : i64
%50 = llvm.alloca %49 x i64 : (i64) -> !llvm.ptr
llvm.store %arg1, %50 : i64, !llvm.ptr
cf.br ^bb6
^bb6:
%51 = llvm.load %50 : !llvm.ptr -> i64
%52 = arith.cmpi sle, %51, %arg0 : i64
cf.cond_br %52, ^bb7, ^bb8
^bb7:
%53 = llvm.load %48 : !llvm.ptr -> i64
%54 = llvm.load %50 : !llvm.ptr -> i64
%55 = arith.divsi %arg0, %54 : i64
%56 = arith.addi %53, %55 : i64
llvm.store %56, %48 : i64, !llvm.ptr
%57 = llvm.load %50 : !llvm.ptr -> i64
%58 = arith.divsi %arg0, %arg1 : i64
%59 = arith.cmpi sgt, %57, %58 : i64
cf.cond_br %59, ^bb9, ^bb10
^bb9:
cf.br ^bb8
^bb10:
cf.br ^bb11
^bb11:
%60 = llvm.load %50 : !llvm.ptr -> i64
%61 = arith.muli %60, %arg1 : i64
llvm.store %61, %50 : i64, !llvm.ptr
cf.br ^bb6
^bb8:
%62 = llvm.load %48 : !llvm.ptr -> i64
func.return %62 : i64
}
func.func @main() -> i32 {
%63 = arith.constant 100000000 : i32
%64 = arith.extsi %63 : i32 to i64
%65 = arith.constant 1000000009 : i32
%66 = arith.extsi %65 : i32 to i64
%67 = arith.constant 1 : i32
%69 = arith.extsi %67 : i32 to i64
%68 = arith.shrsi %64, %69 : i64
%70 = arith.constant 1 : i32
%72 = arith.extsi %70 : i32 to i64
%71 = arith.addi %68, %72 : i64
%74 = arith.constant 1 : i32
%75 = arith.extsi %74 : i32 to i64
%73 = func.call @calloc(%71, %75) : (i64, i64) -> !llvm.ptr
%76 = llvm.mlir.zero : !llvm.ptr
%77 = llvm.icmp "eq" %73, %76 : !llvm.ptr
cf.cond_br %77, ^bb12, ^bb13
^bb12:
%78 = arith.constant 1 : i32
func.return %78 : i32
^bb13:
cf.br ^bb14
^bb14:
%79 = arith.constant 1 : i32
%80 = arith.constant 0 : i32
%81 = arith.trunci %79 : i32 to i8
%82 = arith.extsi %80 : i32 to i64
%83 = llvm.getelementptr %73[%82] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %81, %83 : i8, !llvm.ptr
%84 = arith.constant 1 : i32
%85 = arith.extsi %84 : i32 to i64
%86 = llvm.mlir.constant(1 : i64) : i64
%87 = llvm.alloca %86 x i64 : (i64) -> !llvm.ptr
llvm.store %85, %87 : i64, !llvm.ptr
cf.br ^bb15
^bb15:
%88 = arith.constant 2 : i32
%89 = llvm.load %87 : !llvm.ptr -> i64
%91 = arith.extsi %88 : i32 to i64
%90 = arith.muli %91, %89 : i64
%92 = llvm.load %87 : !llvm.ptr -> i64
%93 = arith.muli %90, %92 : i64
%94 = arith.cmpi slt, %93, %71 : i64
cf.cond_br %94, ^bb16, ^bb17
^bb16:
%96 = llvm.load %87 : !llvm.ptr -> i64
%97 = llvm.getelementptr %73[%96] : (!llvm.ptr, i64) -> !llvm.ptr, i8
%95 = llvm.load %97 : !llvm.ptr -> i8
%98 = arith.constant 0 : i32
%100 = arith.extsi %95 : i8 to i32
%99 = arith.cmpi eq, %100, %98 : i32
cf.cond_br %99, ^bb18, ^bb19
^bb18:
%101 = arith.constant 3 : i32
%102 = llvm.load %87 : !llvm.ptr -> i64
%104 = arith.extsi %101 : i32 to i64
%103 = arith.muli %104, %102 : i64
%105 = arith.constant 1 : i32
%107 = arith.extsi %105 : i32 to i64
%106 = arith.addi %103, %107 : i64
%108 = llvm.mlir.constant(1 : i64) : i64
%109 = llvm.alloca %108 x i64 : (i64) -> !llvm.ptr
llvm.store %106, %109 : i64, !llvm.ptr
%110 = arith.constant 2 : i32
%111 = llvm.load %87 : !llvm.ptr -> i64
%113 = arith.extsi %110 : i32 to i64
%112 = arith.muli %113, %111 : i64
%114 = arith.constant 1 : i32
%116 = arith.extsi %114 : i32 to i64
%115 = arith.addi %112, %116 : i64
cf.br ^bb21
^bb21:
%117 = llvm.load %109 : !llvm.ptr -> i64
%118 = arith.cmpi slt, %117, %71 : i64
cf.cond_br %118, ^bb22, ^bb23
^bb22:
%119 = arith.constant 1 : i32
%120 = llvm.load %109 : !llvm.ptr -> i64
%121 = arith.trunci %119 : i32 to i8
%122 = llvm.getelementptr %73[%120] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %121, %122 : i8, !llvm.ptr
%123 = llvm.load %109 : !llvm.ptr -> i64
%124 = arith.addi %123, %115 : i64
llvm.store %124, %109 : i64, !llvm.ptr
cf.br ^bb21
^bb23:
cf.br ^bb20
^bb19:
cf.br ^bb20
^bb20:
%125 = llvm.load %87 : !llvm.ptr -> i64
%126 = arith.constant 1 : i32
%128 = arith.extsi %126 : i32 to i64
%127 = arith.addi %125, %128 : i64
llvm.store %127, %87 : i64, !llvm.ptr
cf.br ^bb15
^bb17:
%129 = arith.constant 1 : i32
%130 = arith.extsi %129 : i32 to i64
%131 = llvm.mlir.constant(1 : i64) : i64
%132 = llvm.alloca %131 x i64 : (i64) -> !llvm.ptr
llvm.store %130, %132 : i64, !llvm.ptr
%134 = arith.constant 2 : i32
%135 = arith.extsi %134 : i32 to i64
%133 = func.call @count_factors(%64, %135) : (i64, i64) -> i64
%136 = llvm.load %132 : !llvm.ptr -> i64
%137 = arith.constant 1 : i32
%139 = arith.constant 2 : i32
%140 = arith.constant 2 : i32
%142 = arith.extsi %140 : i32 to i64
%141 = arith.muli %142, %133 : i64
%143 = arith.extsi %139 : i32 to i64
%138 = func.call @modpow(%143, %141, %66) : (i64, i64, i64) -> i64
%145 = arith.extsi %137 : i32 to i64
%144 = arith.addi %145, %138 : i64
%146 = arith.muli %136, %144 : i64
%147 = arith.remsi %146, %66 : i64
llvm.store %147, %132 : i64, !llvm.ptr
%148 = arith.constant 3 : i32
%149 = arith.extsi %148 : i32 to i64
%150 = llvm.mlir.constant(1 : i64) : i64
%151 = llvm.alloca %150 x i64 : (i64) -> !llvm.ptr
llvm.store %149, %151 : i64, !llvm.ptr
cf.br ^bb24
^bb24:
%152 = llvm.load %151 : !llvm.ptr -> i64
%153 = arith.cmpi sle, %152, %64 : i64
cf.cond_br %153, ^bb25, ^bb26
^bb25:
%155 = llvm.load %151 : !llvm.ptr -> i64
%156 = arith.constant 1 : i32
%158 = arith.extsi %156 : i32 to i64
%157 = arith.shrsi %155, %158 : i64
%159 = llvm.getelementptr %73[%157] : (!llvm.ptr, i64) -> !llvm.ptr, i8
%154 = llvm.load %159 : !llvm.ptr -> i8
%160 = arith.constant 0 : i32
%162 = arith.extsi %154 : i8 to i32
%161 = arith.cmpi eq, %162, %160 : i32
cf.cond_br %161, ^bb27, ^bb28
^bb27:
%164 = llvm.load %151 : !llvm.ptr -> i64
%163 = func.call @count_factors(%64, %164) : (i64, i64) -> i64
%165 = llvm.load %132 : !llvm.ptr -> i64
%166 = arith.constant 1 : i32
%168 = llvm.load %151 : !llvm.ptr -> i64
%169 = arith.constant 2 : i32
%171 = arith.extsi %169 : i32 to i64
%170 = arith.muli %171, %163 : i64
%167 = func.call @modpow(%168, %170, %66) : (i64, i64, i64) -> i64
%173 = arith.extsi %166 : i32 to i64
%172 = arith.addi %173, %167 : i64
%174 = arith.muli %165, %172 : i64
%175 = arith.remsi %174, %66 : i64
llvm.store %175, %132 : i64, !llvm.ptr
cf.br ^bb29
^bb28:
cf.br ^bb29
^bb29:
%176 = llvm.load %151 : !llvm.ptr -> i64
%177 = arith.constant 2 : i32
%179 = arith.extsi %177 : i32 to i64
%178 = arith.addi %176, %179 : i64
llvm.store %178, %151 : i64, !llvm.ptr
cf.br ^bb24
^bb26:
%180 = llvm.mlir.addressof @str_0 : !llvm.ptr
%181 = llvm.load %132 : !llvm.ptr -> i64
%182 = llvm.call @printf(%180, %181) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr, i64) -> i32
func.call @free(%73) : (!llvm.ptr) -> ()
%184 = arith.constant 0 : i32
func.return %184 : i32
}
}