汇编语言-求所有的素因子

  求给定整数的所有素因子

1. 题目：求给定整数的所有素因子

2. 要求：输入一个整数，求出其所有素因子，并表现为乘积方式，求因子的算法用子程序来实现。例如，输入480,输出480=2*2*2*2*2*3*5

 

C++代码如下

 1 //The program is to find all the prime factors of a number
 2 //Author:Karllen
 3 //Date: 05/22/2014
 4 #include <iostream>
 5 
 6 void findPfactor(int n);      // Find the factor belongs to prime
 7 int  main(void)
 8 {
 9     int n;
10     std::cin>>n;
11     findPfactor(n);
12     system("pause");
13     return 0;
14 }
15 
16 void findPfactor(int n)
17 {
18     int i = 2;
19     while (i<n)
20     {
21         while (n%i==0)       //The i is a factor of n
22         {
23             n = n/i;
24             std::cout<<i;    
25             std::cout<<'*';
26         } 
27         ++i;
28     }
29     std::cout<<n<<std::endl;
30 }

汇编代码如下：

  1 ; Example assembly language program
  2 ; Author:  Karllen
  3 ; Date:    revised 05/2014
  4 
  5 .386
  6 .MODEL FLAT
  7 
  8 ExitProcess PROTO NEAR32 stdcall, dwExitCode:DWORD
  9 
 10 INCLUDE io.h            ; header file for input/output
 11 
 12 cr      EQU     0dh     ; carriage return character
 13 Lf      EQU     0ah     ; line feed
 14 
 15 .STACK  4096            ; reserve 4096-byte stack
 16 
 17 .DATA                   ; reserve storage for data
 18        flai     DWORD ?
 19        temp     DWORD ?
 20        crlf     BYTE "*",0
 21        eqll     BYTE "=",0
 22        prompt   BYTE "Enter a number to find all the prime factors",cr,Lf,0
 23        fl       DWORD ?
 24        value    BYTE 11 DUP(?),0
 25        char     BYTE 1 DUP(?)
 26    
 27  PUBLIC _start        
 28 .CODE                           ; start of main program code
 29 _start:
 30        output  prompt
 31        input   value,11
 32        atod    value
 33        push    eax
 34        call    byteInput
 35        add     esp,4
 36        
 37        output  eqll
 38        
 39        push    eax
 40        call    findPfactor
 41        add     esp,4
 42        
 43         INVOKE  ExitProcess, 0  ; exit with return code 0
 44 
 45                 
 46 findPfactor PROC NEAR32         ;find the prime of factor
 47           push ebp
 48           mov  ebp,esp
 49           
 50           mov  eax,[ebp+8]
 51           mov  flai,eax
 52           mov  ecx,2
 53           mov  ebx,ecx
 54           doFind:
 55                mov ecx,ebx
 56                cmp ecx,flai
 57                je  endFind
 58                doFactor:
 59                    mov temp,eax
 60                    cdq
 61                    idiv ecx
 62                    ;eax = eax/ecx
 63                    cmp edx,0
 64                    jne endFactor
 65                    ;dtoa value,ecx
 66                    ;output value
 67                    push ecx
 68                    call byteInput
 69                    add esp,4
 70                    output crlf
 71                    
 72                    jmp  doFactor
 73                endFactor:
 74                     mov eax,temp
 75                     inc ebx
 76                     jmp doFind               
 77           endFind:         
 78           pop  ebp
 79           ret 
 80       
 81 findPfactor ENDP
 82 
 83 byteInput PROC NEAR32
 84           push ebp
 85           mov  ebp,esp
 86           
 87           push ebx
 88           push eax
 89           push edx
 90           
 91           mov  fl,0
 92           mov  ebx,10
 93           mov  eax,[ebp+8]
 94           doWh:
 95               cdq
 96               idiv ebx
 97               push edx
 98               inc fl
 99               cmp eax,0
100               je  enddoWh
101               
102              
103               jmp doWh
104           enddoWh: 
105           
106           doPrint:
107                  
108                  cmp fl,0
109                  je  enddoPrint
110                  dec fl
111                  pop edx 
112                  mov char,dl
113                  add char,'0'
114                  output char
115                  jmp doPrint
116           enddoPrint:
117           pop edx
118           pop eax
119           pop ebx
120           pop ebp
121           ret
122           
123 byteInput ENDP
124 
125 END                             ; end of source code

测试结果：

posted @ 2014-05-22 23:44  karllen  阅读(717)  评论(0)  编辑  收藏  举报