颠倒字符串中的单词

I am student 变成 student am I

#include<iostream>
using namespace std;
void reverse(char *str,int n)
{
	char* p = str+n-1;
	while (str<p) {
		char c = *str;
		*str = *p; *p=c;
		str++;p--;
	}
}
int main()
{
	char s[100];
	while(gets(s))
	{
		reverse(s,strlen(s));
		int i=0,j=0;
		while(s[i])
		{
			if(s[i]==' ')
			{
				reverse(s+j,i-j);//注意函数中的n是长度
				i++;j=i;
			}
			else i++;
		}
		reverse(s+j,i-j);
		puts(s);
	}
	return 0;
}