Problem 112

Least n such that the proportion of bouncy numbers is exactly 99%.

View problem on Project Euler

Performance comparison

Flow source

# Project Euler 112
# Least n such that the proportion of bouncy numbers is exactly 99%.

function is_bouncy(n0: i64) -> bool {
    let mut n: i64 = n0
    let mut prev: i64 = n % 10
    n = n / 10
    let mut inc: bool = false
    let mut dec: bool = false
    while n > 0 {
        let d: i64 = n % 10
        if d < prev { inc = true }
        if d > prev { dec = true }
        if inc && dec { return true }
        prev = d
        n = n / 10
    }
    return false
}

function main() -> i32 {
    let mut bouncy: i64 = 0
    let mut n: i64 = 1
    while true {
        if is_bouncy(n) {
            bouncy = bouncy + 1
        }
        if n > 100 && bouncy * 100 == n * 99 {
            printf("%lld\n", n)
            return 0
        }
        n = n + 1
        if n > 10000000 {
            printf("0\n")
            return 1
        }
    }
    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; }

bool is_bouncy_i64(int64_t n0);
int32_t main(void);

bool is_bouncy_i64(int64_t n0) {
    int64_t n = n0;
    int64_t prev = FLOW_CHECKED_MOD((n), (10));
    n = FLOW_CHECKED_DIV((n), (10));
    bool inc = 0;
    bool dec = 0;
    while (n > 0) {
        int64_t d = FLOW_CHECKED_MOD((n), (10));
        if (d < prev) {
            inc = 1;
        }
        if (d > prev) {
            dec = 1;
        }
        if ((inc && dec)) {
            return 1;
        }
        prev = d;
        n = FLOW_CHECKED_DIV((n), (10));
    }
    return 0;
}

int32_t main(void) {
    int64_t bouncy = 0;
    int64_t n = 1;
    while (1) {
        if (is_bouncy_i64(n)) {
            bouncy = (bouncy + 1);
        }
        if ((n > 100 && (bouncy * 100) == (n * 99))) {
            printf("%lld\n", n);
            return 0;
        }
        n = (n + 1);
        if (n > 10000000) {
            printf("0\n");
            return 1;
        }
    }
    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>
  llvm.mlir.global internal constant @str_1("0\n\00") {addr_space = 0 : i32} : !llvm.array<3 x i8>
  func.func @is_bouncy(%arg0: i64) -> i1 {
    %0 = llvm.mlir.constant(1 : i64) : i64
    %1 = llvm.alloca %0 x i64 : (i64) -> !llvm.ptr
    llvm.store %arg0, %1 : i64, !llvm.ptr
    %2 = llvm.load %1 : !llvm.ptr -> i64
    %3 = arith.constant 10 : i32
    %5 = arith.extsi %3 : i32 to i64
    %4 = arith.remsi %2, %5 : i64
    %6 = llvm.mlir.constant(1 : i64) : i64
    %7 = llvm.alloca %6 x i64 : (i64) -> !llvm.ptr
    llvm.store %4, %7 : i64, !llvm.ptr
    %8 = llvm.load %1 : !llvm.ptr -> i64
    %9 = arith.constant 10 : i32
    %11 = arith.extsi %9 : i32 to i64
    %10 = arith.divsi %8, %11 : i64
    llvm.store %10, %1 : i64, !llvm.ptr
    %12 = arith.constant 0 : i1
    %13 = llvm.mlir.constant(1 : i64) : i64
    %14 = llvm.alloca %13 x i1 : (i64) -> !llvm.ptr
    llvm.store %12, %14 : i1, !llvm.ptr
    %15 = arith.constant 0 : i1
    %16 = llvm.mlir.constant(1 : i64) : i64
    %17 = llvm.alloca %16 x i1 : (i64) -> !llvm.ptr
    llvm.store %15, %17 : i1, !llvm.ptr
    cf.br ^bb0
    ^bb0:
    %18 = llvm.load %1 : !llvm.ptr -> i64
    %19 = arith.constant 0 : i32
    %21 = arith.extsi %19 : i32 to i64
    %20 = arith.cmpi sgt, %18, %21 : i64
    cf.cond_br %20, ^bb1, ^bb2
    ^bb1:
      %22 = llvm.load %1 : !llvm.ptr -> i64
      %23 = arith.constant 10 : i32
      %25 = arith.extsi %23 : i32 to i64
      %24 = arith.remsi %22, %25 : i64
      %26 = llvm.load %7 : !llvm.ptr -> i64
      %27 = arith.cmpi slt, %24, %26 : i64
      cf.cond_br %27, ^bb3, ^bb4
      ^bb3:
        %28 = arith.constant 1 : i1
        llvm.store %28, %14 : i1, !llvm.ptr
        cf.br ^bb5
      ^bb4:
        cf.br ^bb5
      ^bb5:
      %29 = llvm.load %7 : !llvm.ptr -> i64
      %30 = arith.cmpi sgt, %24, %29 : i64
      cf.cond_br %30, ^bb6, ^bb7
      ^bb6:
        %31 = arith.constant 1 : i1
        llvm.store %31, %17 : i1, !llvm.ptr
        cf.br ^bb8
      ^bb7:
        cf.br ^bb8
      ^bb8:
      %32 = llvm.load %14 : !llvm.ptr -> i1
      %33 = scf.if %32 -> (i1) {
        %34 = llvm.load %17 : !llvm.ptr -> i1
        scf.yield %34 : i1
      } else {
        %35 = arith.constant false
        scf.yield %35 : i1
      }
      cf.cond_br %33, ^bb9, ^bb10
      ^bb9:
        %36 = arith.constant 1 : i1
        func.return %36 : i1
      ^bb10:
        cf.br ^bb11
      ^bb11:
      llvm.store %24, %7 : i64, !llvm.ptr
      %37 = llvm.load %1 : !llvm.ptr -> i64
      %38 = arith.constant 10 : i32
      %40 = arith.extsi %38 : i32 to i64
      %39 = arith.divsi %37, %40 : i64
      llvm.store %39, %1 : i64, !llvm.ptr
      cf.br ^bb0
    ^bb2:
    %41 = arith.constant 0 : i1
    func.return %41 : i1
  }
  func.func @main() -> i32 {
    %42 = arith.constant 0 : i32
    %43 = arith.extsi %42 : i32 to i64
    %44 = llvm.mlir.constant(1 : i64) : i64
    %45 = llvm.alloca %44 x i64 : (i64) -> !llvm.ptr
    llvm.store %43, %45 : i64, !llvm.ptr
    %46 = arith.constant 1 : i32
    %47 = arith.extsi %46 : i32 to i64
    %48 = llvm.mlir.constant(1 : i64) : i64
    %49 = llvm.alloca %48 x i64 : (i64) -> !llvm.ptr
    llvm.store %47, %49 : i64, !llvm.ptr
    cf.br ^bb12
    ^bb12:
    %50 = arith.constant 1 : i1
    cf.cond_br %50, ^bb13, ^bb14
    ^bb13:
      %52 = llvm.load %49 : !llvm.ptr -> i64
      %51 = func.call @is_bouncy(%52) : (i64) -> i1
      cf.cond_br %51, ^bb15, ^bb16
      ^bb15:
        %53 = llvm.load %45 : !llvm.ptr -> i64
        %54 = arith.constant 1 : i32
        %56 = arith.extsi %54 : i32 to i64
        %55 = arith.addi %53, %56 : i64
        llvm.store %55, %45 : i64, !llvm.ptr
        cf.br ^bb17
      ^bb16:
        cf.br ^bb17
      ^bb17:
      %57 = llvm.load %49 : !llvm.ptr -> i64
      %58 = arith.constant 100 : i32
      %60 = arith.extsi %58 : i32 to i64
      %59 = arith.cmpi sgt, %57, %60 : i64
      %61 = scf.if %59 -> (i1) {
        %62 = llvm.load %45 : !llvm.ptr -> i64
        %63 = arith.constant 100 : i32
        %65 = arith.extsi %63 : i32 to i64
        %64 = arith.muli %62, %65 : i64
        %66 = llvm.load %49 : !llvm.ptr -> i64
        %67 = arith.constant 99 : i32
        %69 = arith.extsi %67 : i32 to i64
        %68 = arith.muli %66, %69 : i64
        %70 = arith.cmpi eq, %64, %68 : i64
        scf.yield %70 : i1
      } else {
        %71 = arith.constant false
        scf.yield %71 : i1
      }
      cf.cond_br %61, ^bb18, ^bb19
      ^bb18:
        %72 = llvm.mlir.addressof @str_0 : !llvm.ptr
        %73 = llvm.load %49 : !llvm.ptr -> i64
        %74 = llvm.call @printf(%72, %73) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr, i64) -> i32
        %75 = arith.constant 0 : i32
        func.return %75 : i32
      ^bb19:
        cf.br ^bb20
      ^bb20:
      %76 = llvm.load %49 : !llvm.ptr -> i64
      %77 = arith.constant 1 : i32
      %79 = arith.extsi %77 : i32 to i64
      %78 = arith.addi %76, %79 : i64
      llvm.store %78, %49 : i64, !llvm.ptr
      %80 = llvm.load %49 : !llvm.ptr -> i64
      %81 = arith.constant 10000000 : i32
      %83 = arith.extsi %81 : i32 to i64
      %82 = arith.cmpi sgt, %80, %83 : i64
      cf.cond_br %82, ^bb21, ^bb22
      ^bb21:
        %84 = llvm.mlir.addressof @str_1 : !llvm.ptr
        %85 = llvm.call @printf(%84) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr) -> i32
        %86 = arith.constant 1 : i32
        func.return %86 : i32
      ^bb22:
        cf.br ^bb23
      ^bb23:
      cf.br ^bb12
    ^bb14:
    %87 = arith.constant 0 : i32
    func.return %87 : i32
  }
}