[daily question 1] write a function to judge whether a string is the string after the rotation of another string.

Write a function , To determine whether a string is the rotated string of another string .

for example ： Given s1 =AABCD and s2 = BCDAA, return 1

Given s1=abcd and s2=ACBD, return 0.

AABCD Turn a character left to get ABCDA

AABCD Two left-handed characters get BCDAA

AABCD Turn one character right to get DAABC

Scheme 1

analysis ：s1 Rotate once as ABCDA, and s2 Compare , call strcmp, The return value is equal to 0 Value , It means yes s2 yes s1 Spin to get , Otherwise, continue to ABCDA Rotate again on the basis of , obtain BCDAA, and s2 Compare , call strcmp, The return value is equal to 0 Value , It means yes s2 yes s1 Spin to get , Continue to cycle , Until the cycle 5 Time , Or just meet in the cycle s1=s2, It means that ,s2 yes s1 Spin to get .

# define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include<string.h>
int judge(char* s1, char* s2,int len)
{
    	
// First rotate one character 
	for (int i = 1; i <= len; ++i)	
	{
    	//i by 1 First rotation 
		char tem = *s1;
		int j=0;
		for (j = 0; j < len; ++j)
		{
    
			*(s1 + j) = *(s1 + j + 1);
		}
		*(s1+j) = tem;// Put the value just taken out into the last element 
		if (strcmp(s1, s2) == 0)
		{
    
			return 1;
		}
	}
}
int main()
{
    
	char s1[] = "AABCD";
	char s2[] = "BCDAA";
	int len = strlen(s1);
	if (judge(s1,s2,len))
	
		printf("Fing it");	
	else
			printf("No find");
	
	return 0;
}

programme 2

Using functions strcat Make a new string s3,AABCDAABCD, use s2 To traverse whether the comparison function is s1 Subfunction of , If so s2 yes s1 Spin to get .

strncat function

Append characters of a string.

char *strncat(char *strDest,constchar *strSource,size_tcount);

# define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include<string.h>
int FlipCheck(char* arr1, char* arr2)
{
    
	if (strlen(arr1) != strlen(arr2))// If two strings are not equal in length , Then don't compare until it's not the result of rotation .
		return 0;
	strncat(arr1, arr1, strlen(arr1));//append a string
	return strstr(arr1, arr2) != NULL;// Find substrings , If found, the return value is non 0

}
int main()
{
    

	char arr1[20] = "AABCD";
	char arr2[10] = "BCDAA";
	if (FlipCheck(arr1, arr2))
		printf("Find it");
	else
		printf("NO Find");
  return 0;
}

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Today's rubbish ： That company called me again , Ah ah