#include <math.h>
#include <stdio.h>
#include<string>
void CRC(char msg[],char gx[])
{
    int i=0,j=0;
    char c[50];
    int m,n;
   
   
        m=strlen(msg);
        n=strlen(gx);

   
    /*将msg的值赋给c*/
    for(i=0;i<m;i++)
    {
        c[i]=msg[i];
    }
   
   
   
   
    for(i=m;i<m+n-1;i++)
    {
        c[i]=0;
    }

   
   
   
   
   
    for(i=0;i<m;i++)
    {
        if(c[i]==0) continue;
        else
        {
            for(j=0;j<n;j++)
            {
                c[i+j]=c[i+j]^gx[j];
            }
        }
    }

   
   
   
    for(i=0;i<n-1;i++)
    {
        msg[m+i]=c[m+i];
    }

   
   
   
   
    printf("The CRC:");    /*输出循环冗余码:数组msg[m+n-1]    */
   
    for(i=0;i<m+n-1;i++)
    {
        printf("%c",msg[i]);
    }
    printf("\n");


   

}







void main()
{   char msg[50];
    char gx[20];
   
   
    printf("\ninput the message's information:\n");        /*输入二进制信息(0 ~ m-1) */
   
        scanf("%s",msg);
 
        printf("input the G(x)'s information:\n");        /*输入二进制生成多项式(0 ~ n-1)*/
   
        scanf("%s",gx);
 
   
     CRC(msg,gx);
            
   
}


[ 本帖最后由 小兔子慢慢 于 2010-4-17 09:41 编辑 ]

c[i+j]=c[i+j]^gx[j];由于不知道你这句话要表示什么意思。故后面程序有点看不懂。
但是。单单从C语言规则来说
for(i=0;i<n-1;i++)
    {
        msg[m+i]=c[m+i];
    }

由于msg[m],你已经定义为数量为m的数组了。但是你后面用到了msg[m+i]，这个超出了原定于的数组长度。估计是这样出了错误。
你自己在改改。

c[i+j]=c[i+j]^gx[j];
，#include<string>不行

能讲下你要干嘛 吗？

完全不明白程序意图

crc编码

crc编码

for(i=0;i<m;i++)
    {
        if(c[i]=='0') continue;
        else
        {
            for(j=0;j<n;j++)
            {
                if(c[i+j]==g[j])
                 c[i+j]='1';
               else
                 c[i+j]='0';
            }
        }
    }

crc编码

void CRC(char msg[],char gx[])
{
    int i=0,j=0;
    char c[50];
    int m,n;

    m=strlen(msg);
    n=strlen(gx);
    /*将msg的值赋给c*/
    for(i=0;i<m;i++)
    {
        c[i]=msg[i];
    }

    for(i=m;i<m+n-1;i++)
    {
        c[i]='0';
    }

    for(i=0;i<m;i++)                                                                                             
    {                                                                                                            
        if(c[i]=='0') continue;                                                                                   
        else                                                                                                      
        {                                                                                                         
            for(j=0;j<n;j++)                                                                                      
            {                                                                                                     
               if(c[i+j]==gx[j])                                                                                 
                 c[i+j]='0';                                                                                      
               else                                                                                               
                 c[i+j]='1';                                                                                      
            }                                                                                                     
        }                                                                                                         
    }                                                                                                            
                                                                                                                  
    for(i=0;i<n-1;i++)                                                                                            
    {                                                                                                            
        msg[m+i]=c[m+i];                                                                                          
    }                                                                                                            
    printf("The CRC:");    /*输出循环冗余码:数组msg[m+n-1]    */                                                  
    for(i=0;i<m+n-1;i++)                                                                                          
    {                                                                                                            
        printf("%c",msg[i]);                                                                                      
    }                                                                                                            
    printf("\n");                                                                                                
}