USACO 1.1 Friday

Straightforward brutal force implementation.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

class Checker {
public:
  int day, year, offset;

  Checker() : day(1), year(1900), offset(1) {
    frequentCounterList = {0, 0, 0 , 0, 0, 0, 0, 0};
    month2days = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  }

  void traverse(int n) {
    for (int i = 0; i < n; ++i) {
      for (int month = 1; month <= 12; ++month) {
        day = offset + 12;
        frequentCounterList[day % 7 + 1]++;

        if (month == 2) {
          if (isLeapYear(year))
            offset += 29;
          else
            offset += 28;
        } else
          offset += month2days[month];
      }
      ++year;
    }
  }

  vector<int> getFrequency() const {
    return frequentCounterList;
  }

private:
  vector<int> frequentCounterList;
  vector<int> month2days;

private:
  bool isLeapYear(int year) {
    if (year % 100 == 0)
      return year % 400 == 0;

    return year % 4 == 0;
  };
};

int main() {
  ofstream fout ("friday.out");
  ifstream fin ("friday.in");

  string years;
  getline(fin, years);
  Checker checker;
  checker.traverse(stoi(years));

  auto list = checker.getFrequency();
  fout << list[7] << " " << list[1] << " " <<
  list[2] << " " << list[3] << " " << list[4] << " " << list[5] << " " <<
  list[6] << endl;

  return 0;
}