【C语言实现倒置字符串（例如：I like beijing.打印成：beijing.like I）】

倒置字符串
思路
1 .先整体倒置 I like beijing 倒置后 gnijieb ekil i
2，逐个单词倒置 beijing like i

文章目录

技能点
代码实现
总结

技能点

1：指针的使用 2：gets和scanf的区别

1.指针的使用：
char a[100] 表示定义一个数组，开辟100个连续的内存空间。其中数组名为a
a 表示数组首元素的地址 *start=&a, start 表示指向数组a的指针 *start表示数组的第一个元素，这里是 I
2:gets和scanf的区别
gets
Get a line from the stdin stream
头文件为

gets	scanf
Get a line from the stdin stream	Read formatted data from the standard input stream
头文件
char gets( char buffer );	int scanf( const char *format [,argument]… )
Return Value Each of these functions returns its argument if successful. A NULL pointer indicates an error or end-of-file condition. Use ferror or feof to determine which one has occurred.	Return Value Both scanf and wscanf return the number of fields successfully converted and assigned; the return value does not include fields that were read but not assigned. A return value of 0 indicates that no fields were assigned. The return value is EOF for an error or if the end-of-file character or the end-of-string character is encountered in the first attempt to read a character.

代码实现

# define  _CRT_SECURE_NO_WARNINGS 1
// 把 I LOVE YOU  改写成 YOU LOVE I
#include 

//逆序函数，只要传入首位字符的位置就可以实现逆序
void reverse(char* left ,char *right )
{
	//一次翻转
	while (left < right)
	{
		char tem = *left;
		*left = *right;
		*right = tem;
		left++;
		right--;

	}
}

void reverse_string(char* a)
{
	reverse(a, a+strlen(a)-1);//2.先整体逆序
	//2.每个单词逆序
		while (*a)
		{
			//单词逆序
			char* start = a;
			char* end = a;
			while (*end != ' ' && *end != '')
			{
				end++;//指针++，指向下一个位置

			}
			//结束上述循环时end指向空格或者
			reverse(start, end - 1);//传参时指针
			//下一个单词的逆序
			if (*end != '')//如果不是最后一个单词,则 end+1作为新一个单词的开头
			{
				a = end + 1;//空格后面的一个

			}
			else//是最后一个单词
			{
				 a= end;
			}
	}
}

int main()
{
	char a[100] = { 0 };
	gets(a);//输入一个字符串
	reverse_string(a);
	printf("%s", a);

	return 0;
}

总结

以上就是今天要讲的内容，本文用一个例题简单介绍了指针的使用，欢迎指正交流。

【C语言实现倒置字符串（例如：I like beijing.打印成：beijing.like I）】

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