盟 * 讯 笔试题 十六进制字符转数字

int char2digit(char* str)
{
  int temp = 0;
  int val = 0;
  char c = '/0';
  while ((c = *str++) != '/0')
  {
     if (c>='A' && c<='F')
         val = c-'A'+10;
     else if (c>='a' && c<='f')
         val = c-'a'+10;
        else if (c>='0' && c<='9')
            val = c-'0';
        else
         return -1;
       
        temp = temp<<4;
        temp += val;      
 }
 return temp;   
}