UVa 158 - Calendar

Accepted date: 2016-11-27
Run Time: 0.000
Ranking (as of 2016-11-27): 122 out of 365
Language: C++

For clarifying the problem description, see 158 - Calendar - UVa OJ Board - UVa Online Judge.
For a specified date, calculated the number of days from the date and the number of stars ('*') that should be printed of each anniversary, and then printed the anniversaries that should be printed (i.e., that have at least one stars).

/*
  UVa 158 - Calendar

  To build using Visual Studio 2012:
    cl -EHsc -O2 UVa_158_Calendar.cpp
*/

#include <algorithm>
#include <vector>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cctype>
using namespace std;

const int nr_chars_max = 255;

struct anniversary {
  int i_;
  int d_, m_, p_;
  int nr_days_; // number of days from the specified date
  int nr_stars_; // number of stars that should be printed
  anniversary(int i) : i_(i) {}

  bool operator<(const anniversary& a) const
  {
    if (nr_days_ != a.nr_days_)
      return nr_days_ < a.nr_days_;
    else if (!nr_days_)
      return i_ < a.i_;
    else if (nr_stars_ != a.nr_stars_)
      return nr_stars_ > a.nr_stars_;
    else
      return i_ < a.i_;
  }
};

struct description {
  char s_[nr_chars_max + 1];

  description() {}
};

vector<anniversary> anniversaries;
vector<description> descriptions;

inline bool is_leap_year(int year)
{
  if (!(year % 400))
    return true;
  else if (!(year % 100))
    return false;
  else if (!(year % 4))
    return true;
  else
    return false;
}

int get_number_of_days(int year) // return the number of days of given year
{
  return (is_leap_year(year)) ? 366 : 365;
}

int get_number_of_days(int year, int month, int date)
// return the number of days from the first day of given year
{
  const int nr_days[] = {0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
    // nr_days[i] is the number of days before the first day of i-th month
  const int nr_days_leap_year[] = {0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335};
    // nr_days[i] is the number of days before the first day of i-th month for leap years
  int nd = date;
  nd += (is_leap_year(year)) ? nr_days_leap_year[month] : nr_days[month];
  return nd;
}

const char* stars[] = {
  " *TODAY* ", " *       ", " **      ", " ***     ",
  " ****    ", " *****   ", " ******  ", " ******* "
};

int main()
{
  int year;
  scanf("%d", &year);
  while (getchar() != '\n')
    ;
  char s[nr_chars_max + 1];
  int nr_anniversaries = 0;
  while (true) {
    gets(s);
    if (s[0] != 'A')
      break;
    anniversaries.push_back(anniversary(nr_anniversaries)),
      descriptions.push_back(description());
    char* p;
    anniversary& a = anniversaries.back();
    a.d_ = strtol(&s[1], &p, 10);
    a.m_ = strtol(p, &p, 10);
    a.p_ = strtol(p, &p, 10);
    while (isspace(*p))
      p++;
    strcpy(descriptions.back().s_, p);
    nr_anniversaries++;
  }
  bool printed = false;
  while (s[0] != '#') {
    if (printed)
      putchar('\n');
    else
      printed = true;
    char* p;
    int date = strtol(&s[1], &p, 10);
    int month = strtol(p, NULL, 10);
    int nr_days = get_number_of_days(year, month, date);
    for (int i = 0; i < nr_anniversaries; i++) {
      anniversary& a = anniversaries[i];
      int nr = (a.m_ < month || a.m_ == month && a.d_ < date) ?
        get_number_of_days(year) + get_number_of_days(year + 1, a.m_, a.d_) :
        get_number_of_days(year, a.m_, a.d_);
      a.nr_days_ = nr - nr_days;
      a.nr_stars_ = (a.nr_days_ <= 7) ? a.p_ - a.nr_days_ + 1: -1;
    }
    sort(anniversaries.begin(), anniversaries.end());
    printf("Today is:%3d%3d\n", date, month);
    for (int i = 0; i < nr_anniversaries; i++) {
      const anniversary& a = anniversaries[i];
      if (/* a.nr_days_ > 7 || */ a.nr_stars_ <= 0)
        break;
      printf("%3d%3d%s%s\n", a.d_, a.m_,
        ((a.nr_days_) ? stars[a.nr_stars_] : stars[0]), descriptions[a.i_].s_);
    }
    gets(s);
  }
  return 0;
}