#pragma once

#include <stdio.h>     
#include <stdlib.h>     
#include <string.h>    
#include <ctype.h>

class String {
	friend String operator+(const String& a, const String& b);
	long length;
	char* body;
public:
	String() {
		length = 0;
		body = new char[1];
		body[0] = '\0';
	}

	String(const char* s) {
		length = (long)strlen(s);
		body = new char[length + 1];
		for (long i = 0; i < length; ++i)
			body[i] = s[i];
		body[length] = '\0';
	}
	String(const char* s, char ps) {
		length = (long)strlen(s);
		body = new char[length + 1];
		for (long i = 0; i < length; ++i) {
			body[i] = (s[i] == ps) ? '\n' : s[i];
		}
		body[length] = '\0';
	}
	~String() {
		if (body != NULL) {
			delete[] body;
		}
	}
	void println() const {
		printf("[%s]\n", body);
	}
	void addChar(char c) {
		char* buf = new char[length + 2];
		for (long i = 0; i < length; ++i) {
			buf[i] = body[i];
		}
		buf[length] = c;

		length++;
		//--     
		buf[length] = '\0';
		delete[] body;
		body = buf;
		buf = NULL;
	}
	char* getCharArray() const {
		return body;
	}


	String(int s) {
		length = 0;
		body = new char[1];
		body[0] = '\0';
		if (s >= 0) {
			int s_ = s;
			int size = 1;
			while (s_ >= 10) {
				s_ = s_ / 10;
				size++;
			}
			length = size;
			body = new char[size + 1];
			sprintf(body, "%d", s);
		}
	}

	String(long s) {
		String((long long)s);
	}

	String(long long s) {
		length = 0;
		body = new char[1];
		body[0] = '\0';
		if (s >= 0) {
			long s_ = s;
			long size = 1;
			while (s_ >= 10) {
				s_ = s_ / 10;
				size++;
			}
			length = size;
			body = new char[size + 1];
			sprintf(body, "%lld", s);
		}
	}

	const String& operator=(const String& s) {
		if (body != NULL)
			delete[] body;
		length = s.length;
		body = new char[length + 1];
		for (long i = 0; i < length; ++i)
			body[i] = s.body[i];
		body[length] = '\0';
		return *this;
	}

	static String DQuotes(const String& s) {
		String res;
		res.length = s.length + 2;
		res.body = new char[res.length + 1];
		res.body[0] = '"';
		res.body[res.length - 1] = '"';
		res.body[res.length] = '\0';
		for (long i = 0; i < s.length; ++i)
			res.body[i + 1] = s.body[i];
		return res;
	}

	String Replace(char f, char t) {
		String res;
		res.length = length;
		res.body = new char[length];
		res.body[length] = '\0';
		for (long i = 0; i < length; ++i)
			res.body[i] = (body[i] == f) ? t : body[i];
		return res;
	}
	String Remove(char f) {
		String res;
		for (long i = 0; i < length; ++i) {
			if (body[i] != f)
				res.addChar(body[i]);
		}
		return res;
	}
	bool isEmpty() const {
		return length == 0;
	}
	bool contains(const String& s) const {
		bool res = false;
		bool search_on = false;
		if (s.isEmpty()) return true;
		if (s.length > length) return false;
		long k = 0;
		long start = -1;
		for (long i = 0; i < length; ++i) {
			if (search_on) {
				if (k < s.length) {
					if (body[i] == s.body[k]) {
						k++;
					}
					else {
						//обрыв поиска. 
						search_on = false;
						k = 0;
						start = -1;
					}
				}
				else {
					//printf("starts with %ld", start); 
					return true;
				}
			}
			else {
				if (body[i] == s.body[0]) {
					k = 1;
					start = i;
					search_on = true;
					//printf("search started %d\n", start); 
				}
			}
		}
		if (search_on) {
			//printf("starts with %ld\n", start); 
			res = true;
		}
		return res;
	}
	String toUpper() {
		String res = String(this->getCharArray());
		for (long i = 0; i < length; ++i)
			res.body[i] = toupper(body[i]);
		res.println();
		return res;
	}
	long getLength() {
		return length;
	}
	bool operator==(const String& s) const {
		if (length != s.length) return false;
		for (long i = 0; i < length; ++i) {
			if (body[i] != s.body[i]) return false;
		}
		return true;
	}
	/* регистр.
	 #include <stdio.h>
	#include <ctype.h>

	int main(void) {
		FILE * f;
		int c;

		if ( ! ( f = fopen("file.txt", "r") ) )
			return -1;

		while ( ( c = fgetc(f) ) != EOF )
			putchar( isupper(c) ? tolower(c) : toupper(c) );

		return ( fclose(f) );
	}
	 */
};
   
String operator+(const String& a, const String& b) {
	String res = String();
	res.length = a.length + b.length;
	res.body = new char[res.length + 1];
	for (long i = 0; i < a.length; ++i)
		res.body[i] = a.body[i];
	for (long i = 0; i < b.length; ++i)
		res.body[i + a.length] = b.body[i];
	res.body[res.length] = '\0';
	return res;
}