字符串反转

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

char *ReverseString(char *str)
{
	if(str == NULL)
		return NULL;
	int length = strlen(str);
	for(int i = 0;i < length/2; ++i)
	{
		int temp = str[i];
		str[i] = str[length - 1 - i];
		str[length - 1 - i] = temp;
	}
	return str;
}

int main(void)
{
	char str[100] = "hello world";
	char *p = ReverseString(str);
	printf("%s\n",p);
	return 0;
}