C语言通过三步翻转法实现单词倒置详解

//将一句话的单词进行倒置，标点不导致。
//例如：I like BiJing. 倒置成BiJing. like I
#include<stdio.h>
 
#include<string.h>
 
void reverse(char* left, char* right)
{
	while (left < right)
	{
		char temp = *left;
		*left = *right;
		*right = temp;
		left++;
		right--;
	}
}
 
int main()
{
	char arr[100] = { 0 };
	//I like BiJing.
	gets(arr);
	//三步翻转法
	//1.字符串整体翻转
	// .gniJib ekil I
	int len = strlen(arr);//求字符串长度
	reverse(arr, arr + len - 1);
	//2每个单词翻转
	//BiJing. like I
	char* strat = arr;//*strat指向数组首元素的地址
	while (*strat)//*strat指向'\0'跳出循环
	{
		char* end = strat;//*end指向*strat指向的内容
		while (*end != ' ' && *end != '\0')
		{
			end++;
		}
		//逆序一个单词
		reverse(strat, end - 1);
		if (*strat == ' ')//一个单词倒置结束
		{
			strat = end + 1;
		}
        //整个字符串倒置结束
		else
		{
			strat = end;
		}
	}
	printf("%s\n", arr);
	return 0;
}

void reverse(char* left, char* right)
{
	while (left < right)
	{
		char temp = *left;
		*left = *right;
		*right = temp;
		left++;
		right--;
	}
}