C语言字符串逆排序

方法一：
缺点：需要提前定义大一点的数组

//参数:原始字符串,目标字符串
void reverseStr(char *str,char *dist)
{ 
  int i=0;
  char *p=str;
  while(*p)
  {
    p++;
  }
  while((p-str>0))
  {
    p--;
    dist[i++]=*p; 
  } 
}

int main()
{ 
  char *str="123";
  char dist[10]={0};
  reverseStr(str,dist);
  cout<<dist<<endl;
  return 0;
}

方法二：
缺点：需要申请并释放

//参数:原始字符串,目标字符串
void reverseStr(char *str,char **dist)
{ 
  if(str==NULL)
    return ;
  int i=0;
  char *p=str;
  *dist=new char[strlen(str)+1];
  memset(*dist,0,strlen(str)+1);
  while(*p)
  {
    p++;
  }
  while((p-str>0))
  {
    p--;
    (*dist)[i++]=*p;  
  } 
  (*dist)[i]='\0';
}

int main()
{ 
  char *str="123";
  char *dist={0};
  reverseStr(str,&dist);
  cout<<dist<<endl;
  delete []dist;
  dist=NULL;
  return 0;
}