编写一个函数reverse_string(char * string) 实现：将参数字符串中的字符反向排列。

<strong><span style="font-size:24px;">

#include <stdio.h>
#include <string.h>
void swap(char *p,char *q)
{
char tmp = *p;
*p = *q;
*q = tmp;
}

char * reverse_string(char * string)
{
char *left = string;
char *right= string + strlen(string)-1;
while(left < right)
{
swap(left,right);
left++;
right--;
}
return string;
}
int main()
{
char arr[] = "abcdefgh";
reverse_string(arr);
printf("%s\n",arr);
return 0;
}</span></strong>