题目：

将一句话里的单词导致，标点符号不倒换。例如一句话，"I come from Tianjin."，倒换后的结果为"Tianjin. from come I"。

Code(C):

#include<stdio.h>
#include<string.h>

void change(char *s);
reverse(char *s,int start,int end);

void main()
{
	char s[50];
	printf("请输入字符串\n");
	gets(s);
	change(s);
	printf("到之后的字符串为%s\n",s);
}

void change(char *s)
{
	int len,start,end,i;
	len = strlen(s);
	start = 0;
	end = len-1;
	reverse(s,end);
	end = 0;
	for(i = 0;i < len;)
	{
		if(s[i] != ' ')
		{
			start = i;
			while(s[i] != ' ' && s[i] != '\0')
				i++;
			i = i-1;
			end = i;
			reverse(s,end);;
		}
		i++;
	}

}

reverse(char *s,int end)
{
	char temp;
	while(start < end)
	{
		temp = s[start];
		s[start] = s[end];
		s[end] = temp;
		start++;
		end--;
	}
}