problem.cpp

//
//  main.cpp
//  Problem
//
//  Created by Tarun Sudhams on 2016-03-10.
//  Copyright © 2016 Tarun Sudhams. All rights reserved.
//

#include <iostream>
#include <cmath>
#include <stdio.h>


using namespace std;



bool isLeap(int year)
{
    return ((year % 4 == 0 && year % 100 != 0) || ( year % 400 == 0));
}

int increaseDate(int date) // 20160310
{
    unsigned int day = date % 100; // 10
    unsigned int month = (((date % 10000) - (date % 100)) / 100); // 03
    unsigned int year = ((date % int(pow(10, 8))) - month) / pow(10, 4); // 2016
    
    if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10)
    {
        if (day == 31)
        {
            date = ((year * pow(10, 4)) + ((month + 1) * 100) + 1);
        }
        else
            ++date;
        
    }
    
    else if (month == 4 || month == 6 || month == 9 || month == 11)
    {
        date = day == 30 ? ((year * pow(10, 4)) + ((month + 1) * 100) + 1) : ++date;
        
    }
    
    else if (month == 2)
    {
        if (isLeap(year))
        {
            date = day == 29 ? (year * pow(10, 4)) + ((month + 1) * 100) + 1 : ++date;
        }
        else
        {
            date = day == 28 ? (year * pow(10, 4)) + ((month + 1) * 100) + 1 : ++date;
        }
    }
    
    else
    {
        date = day == 31 ? ((year + 1) * pow(10, 4)) + (100) + 1 : ++date;
        
    }
    return date;
}

int increaseDateBySeven(int date)
{
    for (int i = 0; i < 7; i++)
    {
        date = increaseDate(date);
    }
    
    return date;
}

bool isMonday(int date, int start_day_of_Week, int start_date)
{
    int n = start_day_of_Week;
    
    for (int i = start_date; i < date ; i = increaseDate(i))
    {
        n++;
    }
    
    return n % 7 == 1;
}

bool isFriday(int date, int start_day_of_week, int start_date)
{
    int n = start_day_of_week;
    
    for (int i = start_date; i < date; i = increaseDate(i))
    {
        n++;
    }
    
    return n % 7 == 5;
}

bool isWorkingDay(int date, int start_day_of_week, int start_date)
{
    int n = start_day_of_week;
    
    for (int i = start_date; i < date; i = increaseDate(i))
    {
        n++;
    }
    
    return (n % 7 != 6 && n % 7 != 0);
}

unsigned int convertDateToInt(int year, int month, int day)
{
    return (year * 10000) + (month * 100) + day; // 2016 * 1000 = 20160000; 20160000 + (800)= 20160800 + 1 = 20160801
}


int main()
{
    unsigned int start_date, end_date, day_of_week, n_public, n_annual_leaves, start_day, start_month, start_year, end_day, end_month, end_year, saturdays[100], sundays[100], counter_for_saturdays = 0, counter_of_sundays = 0, public_day, public_month, public_year, public_holidays[n_public];
    char buffer;
    
    cout << "Enter the start date: ";
    cin >> start_year; // 2016
    cin >> buffer;
    cin >> start_month; // 8
    cin >> buffer;
    cin >> start_day;// 1
    
    start_date = convertDateToInt(start_year, start_month, start_day);
    cout << "Enter the end date: ";
    cin >> end_year;
    cin >> buffer;
    cin >> end_month;
    cin >> buffer;
    cin >> end_day;
    
    end_date = convertDateToInt(end_year, end_month, end_day);
    
    cout << "Enter the day of the week: ";
    cin >> day_of_week;
    
    cout << "Enter the number of public holidays in that timeframe: ";
    cin >> n_public;
    
    for (int i = 0; i < n_public; i++)
    {
        cin >> public_year;
        cin >> buffer;
        cin >> public_month;
        cin >> buffer;
        cin >> public_day;
        
        public_holidays[i] = convertDateToInt(public_year, public_month, public_day);
    }
    
    
    cout << "Enter the number of days of annual leaves you plan to take: ";
    cin >> n_annual_leaves;
    
    
    int days[420];
    
    int counter = 0;
    for (int i = start_date; i <= end_date; i = increaseDate(i))
    {
        days[counter] = i;
        ++counter;
    }
    
    int holidays[420];
    
    int counter_for_holidays = 0;
    
    int first_saturday = start_date, first_sunday = start_date;
    
    if (day_of_week == 7)
    {
        for (int i = 0; i < 6; i++)
        {
            first_saturday = increaseDate(first_saturday);
        }
    }
    else
    {
        for (int i = day_of_week; i < 6; i++)
        {
            first_saturday = increaseDate(first_saturday);
        }
    }
    
    if (first_saturday > end_date)
    {
        first_saturday = 0;
    }
    else
    {
        for (int i = first_saturday; i < end_date; i = increaseDateBySeven(i))
        {
            holidays[counter_for_holidays] = i;
            ++counter_for_holidays;
            saturdays[counter_for_saturdays] = i;
            ++counter_for_saturdays;
        }
    }
    
    for (int i = day_of_week; i < 7; i++)
    {
        first_sunday = increaseDate(first_sunday);
    }
    
    if (first_sunday > end_date)
    {
        first_sunday = 0;
    }
    else
    {
        for (int i = first_sunday; i < end_date; i = increaseDateBySeven(i))
        {
            holidays[counter_for_holidays] = i;
            ++counter_for_holidays;
            sundays[counter_of_sundays] = i;
            ++counter_of_sundays;
        }
    }
    
    for (int i = 0; i < n_public; i++)
    {
        holidays[counter_for_holidays] = public_holidays[i];
        ++counter_for_holidays;
    }
    
    int final_holidays[counter_for_holidays];
    
    for (int i = 0; i < counter_for_holidays; i++)
    {
        final_holidays[i] = holidays[i];
    }
    
    sort(final_holidays, final_holidays + counter_for_holidays);
    
    
    int n_holidays = 1, max_holidays = 1;
    
    
    int dates[420], dates_counter = 0;
    
    for (int i = start_date; i < end_date; i = increaseDate(i))
    {
        if ((isWorkingDay(i, day_of_week, start_date)))
        {
            dates[dates_counter] = 0;
        }
        
        else
        {
            dates[dates_counter] = 1;
        }
        dates_counter++;
    }
    
    int new_dates_counter = 0, c = 0;
    
    for (int i = start_date; i < end_date; i = increaseDate(i))
    {
        for (int j = 0; j < n_public; j++)
        {
            if (i == public_holidays[j])
            {
                dates[c] = 1;
                new_dates_counter++;
                break;
            }
        }
        
        c++;
    }
    
    int start_of_sequence = 0, end_point = 0;
    
    for (int i = 0; i < c; i++)
    {
        if (dates[i] == 1)
        {
            n_holidays++;
        }
        else
        {
            if (n_holidays - 1 > max_holidays)
            {
                max_holidays = n_holidays - 1;
                end_point = i;
                start_of_sequence = end_point - max_holidays;
                int additional_sequence_start_point = end_point + n_annual_leaves;
                int additional_sequences_begin_point = start_of_sequence - n_annual_leaves - 1;
                
                if (additional_sequence_start_point < c && dates[additional_sequence_start_point] == 1)
                {
                    int k = additional_sequence_start_point;
                    
                    while (dates[k] == 1)
                    {
                        n_holidays++;
                        k++;
                    }
                    
                    
                    max_holidays = n_holidays - 1;
                }
                
                if (additional_sequences_begin_point < c && dates[additional_sequences_begin_point] == 1)
                {
                    int k = additional_sequences_begin_point;
                    
                    while (dates[k] == 1)
                    {
                        n_holidays++;
                        k--;
                    }
                    
                    max_holidays = n_holidays - 1;
                }
            }
            else
            {
                n_holidays = 1;
            }
        }
    }
    
    if (n_holidays - 1 > max_holidays)
    {
        max_holidays = n_holidays - 1;
        end_point = c;
        start_of_sequence = end_point - n_holidays - 1;
    }
    
    
    if (n_holidays == 1 && max_holidays == 1)
    {
        max_holidays = 0;
    }
    
    max_holidays += n_annual_leaves;
    
    unsigned int day = days[start_of_sequence] % 100; // 10
    unsigned int month = (((days[start_of_sequence] % 10000) - (days[start_of_sequence] % 100)) / 100); // 03
    unsigned int year = ((days[start_of_sequence] % int(pow(10, 8))) - month) / pow(10, 4); // 2016
    
    cout << "The maximum number of consecutive holidays you can take is: " << max_holidays << " \nStarting on: " << year << "/" << month << "/" << day << endl;
}