两种方式，第一，通过指针；第二，通过数组下标

void LoopMove(char * l,char * r)
{
	char temp;
	while(l<r)
	{
		temp = *l;
		*l = *r;
		*r = temp;
		++l;
		--r;
	}
}

void ReverseStr(char * str)
{
	char *l,*r;
	r = str;
	l = str;
	LoopMove(l,r+strlen(str)-1);
	while(*r!='\0')
	{
		l = r+1;
		r = l;
		while(*r!=' ' && *r!='\0')
			++r;
		r = r-1;
		LoopMove(l,r);
		l = r+1;
		r = l;
	}
}

int main()
{
	char str[]="i come from tianjin.";
	cout<<strlen(str)<<endl;
	ReverseStr(str);
	cout<<str<<endl;
	return 0;
}

public class StrReverse {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String str="hello i tianjin.";
		char []s = str.tocharArray();
		reverseWord(s);
		System.out.println(new String(s));
	}
	
	public static void reverseWord(char []s){
		int l = 0;
		int r = 0;
		reverse(s,l,r+s.length-1);
		for(int i=0; i<=s.length;++i){
			if(i==(s.length)||s[i]==' '){//注意顺序，否则越界错误
				r = i-1;
				System.out.println(l+" "+r);
				reverse(s,r);
				System.out.println(new String(s));
				l = i+1;
			}
		}
	}
	
	public static void reverse(char []s,int l,int r){
		char temp;
		for(int i=0; i<=(r-l)/2; i++)
		{
			temp = s[l+i];
			s[l+i] = s[r-i];
			s[r-i] = temp;
		}
	}
}