/*
VIM: let b:lcppflags="-std=c++14 -O2 -pthread -I."
VIM: let b:wcppflags="/O2 /EHsc /DWIN32"
*/
#include "stdafx.h"
#include <iostream>
#include <exception>
#include <string>
#include <chrono>
#include <vector>
#include <algorithm>
#include <queue>
#include <mutex>
#include <condition_variable>
#include <atomic>

/*
	given an array representing a non-negative integer (ex: 123 represented
	as [1,2,3]), return the next integer (output: [1,2,4]).
	run through all edge cases (ex: [9,9,9,9,9,9,9,9] etc)
*/

int dig(char ch) {
	return ch - '0';
}

char chr(int dig) {
	return dig + '0';
}

std::string incr(std::string n) {
	int carry = 1;
	for (size_t i = n.size(); i-- > 0; ) {
		int ds = dig(n[i]) + carry;
		if (ds >= 10) {
			carry = ds / 10;
			ds %= 10;
		}
		else {
			carry = 0;
		}
		n[i] = chr(ds);
	}

	if (carry) {
		return chr(carry) + n;
	}
	else {
		return n;
	}
}

int main()
{
	try {
		auto begin = std::chrono::high_resolution_clock::now();

		std::cout << incr("0") << std::endl;
		std::cout << incr("1") << std::endl;
		std::cout << incr("9") << std::endl;
		std::cout << incr("10") << std::endl;
		std::cout << incr("15") << std::endl;
		std::cout << incr("19") << std::endl;
		std::cout << incr("99") << std::endl;
		std::cout << incr("9999999") << std::endl;

		auto end = std::chrono::high_resolution_clock::now();
		std::chrono::duration<double> seconds = end - begin;
		std::cout << "Time: " << seconds.count() << std::endl;
		return 0;
	}
	catch (const std::exception& e)
	{
		std::cerr << std::endl
			<< "std::exception(\"" << e.what() << "\")." << std::endl;
		return 2;
	}
	catch (...)
	{
		std::cerr << std::endl
			<< "unknown exception." << std::endl;
		return 1;
	}
}