求两个字符串的最大公共字符子串，如"abccade","dgcadde"的最大子串为"cad"

#include
#include
#include
 
 //求两个字符串的最大公共字符子串，如"abccade","dgcadde"的最大子串为"cad"
int GetCommon(char *s1, char *s2, char **r)
{
  int len1 = strlen(s1);
  int len2 = strlen(s2);
  int maxlen = 0; 
  int i = 0, j = 0;
  
 for (i = 0;  i < len1;  i++)
  { 
   for(j = 0; j < len2; j++)
  {
    if (s1[i] == s2[j])
   {
     int as = i, bs = j, count = 1;
     while((as + 1 < len1 )&& (bs + 1 < len2) && (s1[++as] ==s2[++bs]))
       count++;
     if (count > maxlen)
    {
       maxlen = count;
       *r = s1 + i;
     }
   }
  }  
 }  
 return  maxlen;
}
//--
int main()
{ 
    char a[] = "abccadefgh";
    char b[] = "dgcaddefgh";
    char *r;
    int len=0;
    len = GetCommon(a, b , &r);
    printf("Len is %d \n", len);
    printf("Result is %s \n", r);
   return 0; 
}
/*--  E  --*/
谢谢欣赏，欢迎指正。