技術標籤：C語言_家庭作業

有一個字元陣列的內容為:“student a am i”,
請你將陣列的內容改為"i am a student".
要求：
不能使用庫函式。
只能開闢有限個空間（空間個數和字串的長度無關）。

student a am i
i ma a tneduts
i am a student

#include <stdio.h>
int my_strlen(char* str)//計算字串長度
{
	int count = 0;
	while (*str!='\0')
	{
		count++;
		str++;
	}
	return count;
 

}

void reverse(char* arr)//反轉字串
{
	int len = my_strlen(arr);
	char tmp = 0;
	char* left = arr+0;
	char* right = arr + len - 1;
	while (left < right)
	{
		tmp = *left;
		*left = *right;
		*right = tmp;
		left++;
		right--;
	}
}

void reverse_part(char* arr,char* left ,char* right)//部分反轉字串
{
	if (left!=
 
right)
	{
		char tmp = 0;
		while (left < right)
		{
			tmp = *left;
			*left = *right;
			*right = tmp;
			left++;
			right--;
		}
	}
}
int main()
{
	char arr[] = "student a am i";
	reverse(arr);
	//printf("%s\n",arr);//i ma a tneduts\0

	char* left = arr+0;
	char* right = arr+0;
	char
 
* tmp = 0;
	while (1)
	{
		while (*right != ' ' && *right != '\0')
		{
			right++;
		}
		right--;
		reverse_part(arr, left, right);
		tmp = right;
		tmp++;
		if (*tmp == '\0')
		{
			break;
		}
		right += 2;
		left = right;
	}
	printf("%s\n", arr);//i am a student
	return 0;
}