反转字符串
void reverse(char *group,int i,int j)
{
char c;
while(i<j){
c=group[i];
group[i]=group[j];
group[j]=c;
++i;--j;
}
}
void reverse_list_word(char * group,int length)
{
reverse(group,0,length-1);
int first=-1,second=-1,i=0;
while(i<length){
while(i<length && group[i]==' ') ++i;
first=i;
while(i<length && group[i]!=' ') ++i;
second=i-1;
if(first!=-1 && first!=length)
{
reverse(group,first,second);
first =-1;second=-1;
}
}
}