C语言三种方法实现字符串左旋

雨点打透心脏的1/2处 2022-07-15 10:08 191阅读 0赞

#define _CRT_SECURE_NO_WARNINGS 1
    #include<stdio.h>
    #include<stdlib.h>
    #include<string.h>
    #include<assert.h>
    void Left_Spin(char arr[], int len, int k)
    {
    	assert(arr);
    	assert(len > 0);
    	int i = 0;
    	int temp = 0;
    	temp = arr[0];
    	int n = 0;
    	for (n = 0; n < k; n++)
    	{
    		for (i = 0; i < len; i++)
    		{
    			arr[i] = arr[i + 1];
    		}
    		arr[len-1] = temp;
    	}
    }
    int main()
    {
    	int num = 0;
    	char array[] = "abcdef";
    	int len = strlen(array);
    	printf("Please  Enter number:");
    	scanf("%d", &num);
    	printf("Before:%s\n", array);
    	Left_Spin(array,len,num);
    	printf("After:%s\n", array);
    	system("pause");
    	return 0;
    
    }

//方法二：把字符串分成两部分，
    //一部分为：从字符串的开始-左旋的次数-1位置的字符串。
    //另一部分为：左旋的次数-1位置的字符串到结尾的位的位置
    #define _CRT_SECURE_NO_WARNINGS 1
    #include<stdio.h>
    #include<stdlib.h>
    #include<string.h>
    #include<assert.h>
    void Swap(char *x, char *y)
    {
    	*x ^= *y;
    	*y ^= *x;
    	*x ^= *y;
    }
    void Left_Spin(char arr[], int len, int k)
    {
       assert(arr);
       assert(len > 0);
    	char *start = arr;
    	char *middle = arr + (k - 1);
    	char *end = arr + len - 1;
    	while (start < middle)
    	{
    		Swap(start, middle);
    		start++;
    		middle--;
    	}
    	start = arr;
    	middle = arr + (k - 1);
    	while (middle + 1 < end)
    	{
    		Swap(middle + 1, end);
    		middle++;
    		end--;
    	}
    	end = arr + len - 1;
    	while (start < end)
    	{
    		Swap(start, end);
    		start++;
    		end--;
    	}
    }
    int main()
    {
    	int num = 0;
    	char array[] = "abcdef";
    	int len = strlen(array);
    	printf("Please enter number:\n");
    	scanf("%d", &num);
    	num %= len;
    	printf("Before:%s\n", array);
    	Left_Spin(array, len, num);
    	printf("After:%s", array);
    	system("pause");
    	return 0;
    
    }

//方法三：进行开辟双倍字符串空间
    #define _CRT_SECURE_NO_WARNINGS 1
    #include<stdio.h>
    #include<stdlib.h>
    #include<string.h>
    #include<assert.h>
    void Left_Spin(char arr[], int len, int k)
    {
    	assert(arr);
    	assert(len > 0);
    	char *Buff=NULL;
    	char *start_Buff = Buff;
    	Buff = (char*)malloc(2 * len+1);
    	strcpy(Buff, arr);
    	strcat(Buff, arr);
    	strncpy(arr, Buff + k,len);
    }
    int main()
    {
    	int num = 0;
    	char array[] = "abcdef";
    	int len = strlen(array);
    	printf("Please enter number:\n");
    	scanf("%d", &num);
    	num %= len;
    	printf("Before:%s\n", array);
    	Left_Spin(array, len, num);
    	printf("After:%s", array);
    	system("pause");
    	return 0;
    
    }