TaskD-2016

// Task04.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <iostream>
using namespace std;

int _tmain(void)
{
    string str;
    getline(cin, str);
    auto len = str.length();
    vector<unsigned short> num(len);
    transform(begin(str), end(str), begin(num), [](char ch){ return ch - 48; });
    auto sum = 3 - accumulate(begin(num), end(num), 0) % 3;
    auto replace = false;
    for (auto i = 2; i >= 0; i--)
    {
        auto res = find_if(begin(num), end(num), [sum, i](unsigned short s_i){ return (s_i + sum + i * 3) < 10; });
        if (res != end(num))
        {
            *res += (sum + i * 3);
            replace = true;
            break;
        }
    }

    if (!replace)
        num[len-1] -= sum;

    copy(begin(num), end(num), ostream_iterator<unsigned short>(cout));
    return 0;
}