我有以下代码：
#include <iostream>
#include <cmath>
bool primes[21] = {0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0};
int find_last_power(int n, int p){
return (int) std::pow(n, (double) 1/p);
}
long long solve(int n){
long long solution = 1;
for (int i=2; i<=n; i++){
if (primes[i]){
std::cout << "p" << i << " : " << std::pow(i, find_last_power(n, i)) << std::endl;
solution *= static_cast<long long>(std::pow(i, find_last_power(n, i)));
}
}
return solution;
}
int main(){
std::cout << solve(20); return 0;
}
primes是一个n+1布尔值的数组，如果i是素数，则其值primes[i]true，如果i是复合值，则值为 false。find_last_power(n, p)返回小于或等于n的最大p幂的指数(int(。
如果你运行程序，它会写出：
p2 : 16
p3 : 9
p5 : 5
p7 : 7
p11 : 11
p13 : 13
p17 : 17
p19 : 19
214885440 // this is the return value of solve(20)
// it is supposed to be the product of the numbers on the right (16,9...)
但返回的数字不是预期的输出。但是，该程序在调试器中正确运行，这就是为什么我发现很难识别错误的原因。预期输出应232792560。
任何帮助，不胜感激。
根据要求，这里是汇编程序源。
.file "PE_5.cxx"
.text
.section .rdata,"dr"
__ZStL19piecewise_construct:
.space 1
.lcomm __ZStL8__ioinit,1,1
.globl _primes
.data
.align 4
_primes:
.byte 0
.byte 0
.byte 1
.byte 1
.byte 0
.byte 1
.byte 0
.byte 1
.byte 0
.byte 0
.byte 0
.byte 1
.byte 0
.byte 1
.byte 0
.byte 0
.byte 0
.byte 1
.byte 0
.byte 1
.byte 0
.text
.globl __Z15find_last_powerii
.def __Z15find_last_powerii; .scl 2; .type 32; .endef
__Z15find_last_powerii:
LFB1717:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $40, %esp
fildl 12(%ebp)
fld1
fdivp %st, %st(1)
fstpl 4(%esp)
movl 8(%ebp), %eax
movl %eax, (%esp)
call __ZSt3powIidEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_
fnstcw -10(%ebp)
movzwl -10(%ebp), %eax
orb $12, %ah
movw %ax, -12(%ebp)
fldcw -12(%ebp)
fistpl -16(%ebp)
fldcw -10(%ebp)
movl -16(%ebp), %eax
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE1717:
.section .rdata,"dr"
LC2:
.ascii "p "
LC3:
.ascii " : "
.text
.globl __Z5solvei
.def __Z5solvei; .scl 2; .type 32; .endef
__Z5solvei:
LFB1718:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
pushl %ebx
subl $52, %esp
.cfi_offset 3, -12
movl $1, -16(%ebp)
movl $0, -12(%ebp)
movl $2, -20(%ebp)
L6:
movl -20(%ebp), %eax
cmpl 8(%ebp), %eax
jg L4
movl -20(%ebp), %eax
addl $_primes, %eax
movzbl (%eax), %eax
testb %al, %al
je L5
movl $LC2, 4(%esp)
movl $__ZSt4cout, (%esp)
call __ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
movl %eax, %edx
movl -20(%ebp), %eax
movl %eax, (%esp)
movl %edx, %ecx
call __ZNSolsEi
subl $4, %esp
movl $LC3, 4(%esp)
movl %eax, (%esp)
call __ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
movl %eax, %ebx
movl -20(%ebp), %eax
movl %eax, 4(%esp)
movl 8(%ebp), %eax
movl %eax, (%esp)
call __Z15find_last_powerii
movl %eax, 4(%esp)
movl -20(%ebp), %eax
movl %eax, (%esp)
call __ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_
fstpl (%esp)
movl %ebx, %ecx
call __ZNSolsEd
subl $8, %esp
movl $__ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_, (%esp)
movl %eax, %ecx
call __ZNSolsEPFRSoS_E
subl $4, %esp
movl -20(%ebp), %eax
movl %eax, 4(%esp)
movl 8(%ebp), %eax
movl %eax, (%esp)
call __Z15find_last_powerii
movl %eax, 4(%esp)
movl -20(%ebp), %eax
movl %eax, (%esp)
call __ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_
fnstcw -26(%ebp)
movzwl -26(%ebp), %eax
orb $12, %ah
movw %ax, -28(%ebp)
fldcw -28(%ebp)
fistpq -40(%ebp)
fldcw -26(%ebp)
movl -40(%ebp), %eax
movl -36(%ebp), %edx
movl -12(%ebp), %ecx
movl %ecx, %ebx
imull %eax, %ebx
movl -16(%ebp), %ecx
imull %edx, %ecx
addl %ebx, %ecx
mull -16(%ebp)
addl %edx, %ecx
movl %ecx, %edx
movl %eax, -16(%ebp)
movl %edx, -12(%ebp)
movl %eax, -16(%ebp)
movl %edx, -12(%ebp)
L5:
addl $1, -20(%ebp)
jmp L6
L4:
movl -16(%ebp), %eax
movl -12(%ebp), %edx
movl -4(%ebp), %ebx
leave
.cfi_restore 5
.cfi_restore 3
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE1718:
.def ___main; .scl 2; .type 32; .endef
.globl _main
.def _main; .scl 2; .type 32; .endef
_main:
LFB1719:
.cfi_startproc
leal 4(%esp), %ecx
.cfi_def_cfa 1, 0
andl $-16, %esp
pushl -4(%ecx)
pushl %ebp
.cfi_escape 0x10,0x5,0x2,0x75,0
movl %esp, %ebp
pushl %ecx
.cfi_escape 0xf,0x3,0x75,0x7c,0x6
subl $20, %esp
call ___main
movl $20, (%esp)
call __Z5solvei
movl %eax, (%esp)
movl %edx, 4(%esp)
movl $__ZSt4cout, %ecx
call __ZNSolsEx
subl $8, %esp
movl $0, %eax
movl -4(%ebp), %ecx
.cfi_def_cfa 1, 0
leave
.cfi_restore 5
leal -4(%ecx), %esp
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE1719:
.section .text$_ZSt3powIidEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_,"x"
.linkonce discard
.globl __ZSt3powIidEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_
.def __ZSt3powIidEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_; .scl 2; .type 32; .endef
__ZSt3powIidEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_:
LFB1955:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $40, %esp
movl 12(%ebp), %eax
movl %eax, -16(%ebp)
movl 16(%ebp), %eax
movl %eax, -12(%ebp)
fildl 8(%ebp)
fldl -16(%ebp)
fstpl 8(%esp)
fstpl (%esp)
call _pow
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE1955:
.section .text$_ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_,"x"
.linkonce discard
.globl __ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_
.def __ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_; .scl 2; .type 32; .endef
__ZSt3powIiiEN9__gnu_cxx11__promote_2IT_T0_NS0_9__promoteIS2_XsrSt12__is_integerIS2_E7__valueEE6__typeENS4_IS3_XsrS5_IS3_E7__valueEE6__typeEE6__typeES2_S3_:
LFB1957:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $24, %esp
fildl 12(%ebp)
fildl 8(%ebp)
fxch %st(1)
fstpl 8(%esp)
fstpl (%esp)
call _pow
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE1957:
.text
.def ___tcf_0; .scl 3; .type 32; .endef
___tcf_0:
LFB2201:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $8, %esp
movl $__ZStL8__ioinit, %ecx
call __ZNSt8ios_base4InitD1Ev
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE2201:
.def __Z41__static_initialization_and_destruction_0ii; .scl 3; .type 32; .endef
__Z41__static_initialization_and_destruction_0ii:
LFB2200:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $24, %esp
cmpl $1, 8(%ebp)
jne L17
cmpl $65535, 12(%ebp)
jne L17
movl $__ZStL8__ioinit, %ecx
call __ZNSt8ios_base4InitC1Ev
movl $___tcf_0, (%esp)
call _atexit
L17:
nop
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE2200:
.def __GLOBAL__sub_I_primes; .scl 3; .type 32; .endef
__GLOBAL__sub_I_primes:
LFB2202:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $24, %esp
movl $65535, 4(%esp)
movl $1, (%esp)
call __Z41__static_initialization_and_destruction_0ii
leave
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE2202:
.section .ctors,"w"
.align 4
.long __GLOBAL__sub_I_primes
.ident "GCC: (MinGW.org GCC-8.2.0-3) 8.2.0"
.def __ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc; .scl 2; .type 32; .endef
.def __ZNSolsEi; .scl 2; .type 32; .endef
.def __ZNSolsEd; .scl 2; .type 32; .endef
.def __ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_; .scl 2; .type 32; .endef
.def __ZNSolsEPFRSoS_E; .scl 2; .type 32; .endef
.def __ZNSolsEx; .scl 2; .type 32; .endef
.def _pow; .scl 2; .type 32; .endef
.def __ZNSt8ios_base4InitD1Ev; .scl 2; .type 32; .endef
.def __ZNSt8ios_base4InitC1Ev; .scl 2; .type 32; .endef
.def _atexit; .scl 2; .type 32; .endef
它是使用以下命令编译的(在64位Intel i5 4690k，Windows 10上(：
g++ -S -o asm.s PE_5.cxx
g++ -c asm.s -o outtput.o
g++ output.o -o out.exe
g++ --version
// g++ (MinGW.org GCC-8.2.0-3) 8.2.0
你有 int 溢出。更改返回的类型
int solve(int n){
跟
long long solve(int n){