#include <iostream>
using namespace std;

//Variant A: zad2
int repetitionCnt(char *s, char *toRepeat)
{
	int repeatLen = strlen(toRepeat);
	int sLen = strlen(s);
	int result = 0;
	for (int i=0;i<sLen;i++)
	{
		if (s[i] == toRepeat[i%repeatLen])
		{
			result++;
		}
		else
		{
			break;
		}
	}
	if (result%repeatLen == 0)
		return result;
	return -1;
}

char * findRepetitionsSubStr(char *b, char *c, int &subStrLen)
{
	int lenB = strlen(b);
	int lenC = strlen(c);
	char *result = NULL;
	subStrLen = -1;
	if ( lenC > lenB)
	{
		return NULL;
	}
	for (int i = 0;i<lenB;i++)
	{
		int currentCnt = repetitionCnt(&b[i],c);
		if ((currentCnt > 0) && (currentCnt > subStrLen))
		{
			result = &b[i];
			subStrLen = currentCnt;
		}
	}
	return result;
}

//Variant B zad 2
char * findSubStr(char *a,char *b, int &skipped)
{
	int aCnt,bCnt;
	int aLen = strlen(a);
	int bLen = strlen(b);
	char *result = NULL;
	for (aCnt=0,bCnt=0; aCnt<aLen; aCnt++)
	{
		if (a[aCnt] == b[bCnt])
		{
			if (!result)
			{
				result = a+aCnt;
			}
			bCnt++;
		}
		else
		{
			skipped++;
		}
		if (bCnt == bLen)
		{
			return result;
		}
	}
	skipped = -1;
	return NULL;
}

//Zad 3 reshenieto i za dvata varianta e ekvivalentno

bool checkLetter(char letter,char *s)
{
	if (strlen(s) == 0)
		return false;
	if (letter == *s)
		return true;
	return checkLetter(letter,s+1);
}

bool checkLetersPresence(char *from, char *in)
{
	if (strlen(from) == 0)
		return true; // stignali sme do kraq i ne sme namerili bukva, koqto da q nqma
		// v protiven sluchai shtqhme da imame false v izraza i negovoto
		// izchislqvane shteshe da e prekrateno.
	return checkLetter(*from,in) && checkLetersPresence(from+1,in);
}

bool equalLetterSets(char *a,char*b)
{
	// mnojestvata suvpadat samo i edinstveno ako kakto vseki element ot a go ima v b
	// taka i obratnoto
	return checkLetersPresence(a,b) && checkLetersPresence(b,a);
}
int main (void)
{
	int len=0;
	char *b = "abcababbbabc";
	char *c = "abcd";
	char *a =  findRepetitionsSubStr(b,c,len);
	if (a) cout << a;
	else cout << "NULL";
	cout <<" ,"<<len<<endl;

	int skipped=0;
	char *A = "abcabvabbbabc";
	char *B = "adbvc";
	char *C =  findSubStr(A,B,skipped);
	if (C) cout << C;
	else cout << "NULL";
	cout <<" ,"<<skipped<<endl;

	char *s1 = "dabcffffff";
	char *s2 = "fabcdn";
	cout<<equalLetterSets(s1,s2)<<endl;
}