Homework 1 Balint

course03/homework00/balint_hw/main.cpp

@@ -0,0 +1,131 @@
+#include <iostream>
+
+class Date {
+private:
+  int y, m, d;
+
+  bool yearvalid() const { return y >= 1600 && y <= 2500; }
+
+  bool monthvalid() const { return m >= 1 && m <= 12; }
+  static bool isleapyear(int y) {
+    if (y % 4 != 0) {
+      return false;
+    }
+    if (y % 100 != 0) {
+      return true;
+    }
+    if (y % 400 != 0) {
+      return false;
+    }
+    return true;
+  }
+  int maxDayInMonth(int y, int m) const {
+    switch (m) {
+    case 1:
+    case 3:
+    case 5:
+    case 7:
+    case 8:
+    case 10:
+    case 12:
+      return 31;
+    case 4:
+    case 6:
+    case 9:
+    case 11:
+      return 30;
+    case 2:
+      return isleapyear(y) ? 29 : 28;
+    default:
+      throw std::runtime_error("Invalid month value");
+    };
+  }
+  int dayDiff(Date first, Date second) const {
+    if (first == second) {
+      return 0;
+    }
+    if (!(first < second)) {
+      return -1 * dayDiff(second, first);
+    }
+
+    Date dayCnt = first.nextDay();
+    int cnt = 1;
+    while (dayCnt < second) {
+      cnt++;
+      dayCnt = dayCnt.nextDay();
+    }
+    return cnt;
+  }
+
+public:
+  Date(int y, int m, int d) : y(y), m(m), d(d){};
+  Date nextDay() const {
+    Date firstguess = {y, m, d + 1};
+    if (!firstguess.isValid()) {
+      firstguess = {y, m + 1, 1};
+      if (!firstguess.isValid()) {
+        firstguess = {y + 1, 1, 1};
+      }
+    }
+    return firstguess;
+  }
+  bool isValid() const {
+    if (!yearvalid() || !monthvalid()) {
+      return false;
+    }
+    if (d < 1 || d > maxDayInMonth(y, m)) {
+      return false;
+    }
+    return true;
+  }
+  int getY() const { return y; }
+  int getM() const { return m; }
+  int getD() const { return d; }
+
+  bool operator==(const Date &other) const {
+    return std::tie(y, m, d) == std::tie(other.y, other.m, other.d);
+  }
+  bool operator<(const Date &other) const {
+    return std::tie(y, m, d) < std::tie(other.y, other.m, other.d);
+  }
+  int daysSinceEpoch() const { return dayDiff({1970, 1, 1}, *this); }
+
+  std::string dayOfWeek() const {
+    if (!isValid()) {
+      throw std::runtime_error("dayOfWeek() called while !isValid()");
+    }
+    int offset = (((daysSinceEpoch() % 7) + 7) % 7);
+    switch (offset) {
+    case 0:
+      return "Thursday";
+    case 1:
+      return "Friday";
+    case 2:
+      return "Saturday";
+    case 3:
+      return "Sunday";
+    case 4:
+      return "Monday";
+    case 5:
+      return "Tuesday";
+    case 6:
+      return "Wednesday";
+    default:
+      throw std::logic_error("Shouldn't happen");
+    }
+  }
+};
+std::ostream &operator<<(std::ostream &strm, const Date &a) {
+  return strm << a.getY() << "-" << a.getM() << "-" << a.getD();
+}
+
+int main() {
+
+  Date test2 = {2019, 5, 5};
+
+  std::cout << "Nr of days since epoch is: " << test2.daysSinceEpoch()
+            << std::endl;
+  std::cout << "Day of week is : " << test2.dayOfWeek() << std::endl;
+
+  return 0;
+}