Completed task

extra-task-1.cpp

@@ -1,169 +1,123 @@
+#include <cassert>
+#include <iostream>
+
+// Return the number of seconds later that a time in seconds time_2
+// is than a time in seconds time_1.
 double seconds_difference(double time_1, double time_2)
 {
-    // your implementation goes here...
-
-    /*    
-        Return the number of seconds later that a time in seconds
-        time_2 is than a time in seconds time_1.
-
-        >>> seconds_difference(1800.0, 3600.0)
-        1800.0
-
-        >>> seconds_difference(3600.0, 1800.0)
-        -1800.0
-
-        >>> seconds_difference(1800.0, 2160.0)
-        360.0
-
-        >>> seconds_difference(1800.0, 1800.0)
-        0.0
-    */
+	return time_2 - time_1;
 }
 
+// Return the number of hours later that a time in seconds time_2
+// is than a time in seconds time_1.
 double hours_difference(double time_1, double time_2)
 {
-    /*
-        Return the number of hours later that a time in seconds
-        time_2 is than a time in seconds time_1.
-
-        >>> hours_difference(1800.0, 3600.0)
-        0.5
-
-        >>> hours_difference(3600.0, 1800.0)
-        -0.5
-
-        >>> hours_difference(1800.0, 2160.0)
-        0.1
-
-        >>> hours_difference(1800.0, 1800.0)
-        0.0
-    */
+	return (time_2 - time_1) / 3600.0;
 }
 
+// Return the total number of hours in the specified number
+// of hours, minutes, and seconds.
 double to_float_hours(int hours, int minutes, int seconds)
 {
-    /*
-        Return the total number of hours in the specified number
-        of hours, minutes, and seconds.
-
-        Precondition: 0 <= minutes < 60  and  0 <= seconds < 60
-
-        >>> to_float_hours(0, 15, 0)
-        0.25
-
-        >>> to_float_hours(2, 45, 9)
-        2.7525
-
-        >>> to_float_hours(1, 0, 36)
-        1.01
-    */
+	return hours + minutes / 60.0 + seconds / 3600.0;
 }
 
+// hours is a number of hours since midnight. Return the hour as seen
+// on a 24-hour clock. 
 double to_24_hour_clock(double hours)
 {
-    /*
-        hours is a number of hours since midnight. Return the
-        hour as seen on a 24-hour clock.
-
-        Precondition: hours >= 0
-
-        >>> to_24_hour_clock(24)
-        0
-
-        >>> to_24_hour_clock(48)
-        0
-
-        >>> to_24_hour_clock(25)
-        1
-
-        >>> to_24_hour_clock(4)
-        4
-
-        >>> to_24_hour_clock(28.5)
-        4.5
-
-        You may wish to inspect various function in <cmath> to work
-        with integer and fractional part of a hours separately.
-
-    */
+	double result = std::fmod(hours, 24.0);
+	if (result < 0) {
+		result += 24.0;
+	}
+	return result;
 }
 
-/*
-    Implement three functions
-        * get_hours
-        * get_minutes
-        * get_seconds
-    They are used to determine the hours part, minutes part and seconds part 
-    of a time in seconds. E.g.:
-
-    >>> get_hours(3800)
-    1
-
-    >>> get_minutes(3800)
-    3
+// Return the hours part of a time in seconds.
+int get_hours(int seconds)
+{
+	if (seconds < 0) return 0;
+	return (seconds / 3600) % 24;
+}
 
-    >>> get_seconds(3800)
-    20
+// Return the minutes part of a time in seconds.
+int get_minutes(int seconds)
+{
+	if (seconds < 0) return 0;
+	return (seconds / 60) % 60;
+}
 
-    In other words, if 3800 seconds have elapsed since midnight, 
-    it is currently 01:03:20 (hh:mm:ss).
-*/
+// Return the seconds part of a time in seconds.
+int get_seconds(int seconds)
+{
+	if (seconds < 0) return 0;
+	return seconds % 60;
+}
 
+// Return time at UTC+0, given a local time and its utc_offset.
 double time_to_utc(int utc_offset, double time)
 {
-    /*
-        Return time at UTC+0, where utc_offset is the number of hours away from
-        UTC+0.
-        You may be interested in:
-        https://en.wikipedia.org/wiki/Coordinated_Universal_Time
-
-        >>> time_to_utc(+0, 12.0)
-        12.0
-
-        >>> time_to_utc(+1, 12.0)
-        11.0
-
-        >>> time_to_utc(-1, 12.0)
-        13.0
-
-        >>> time_to_utc(-11, 18.0)
-        5.0
-
-        >>> time_to_utc(-1, 0.0)
-        1.0
-
-        >>> time_to_utc(-1, 23.0)
-        0.0
-    */
+	double result = time - utc_offset;
+	result = std::fmod(result, 24.0);
+	if (result < 0) {
+		result += 24.0;
+	}
+	return result;
 }
 
+// Return local time in time zone utc_offset, given UTC time.
 double time_from_utc(int utc_offset, double time)
 {
-    /*
-        Return UTC time in time zone utc_offset.
-
-        >>> time_from_utc(+0, 12.0)
-        12.0
-
-        >>> time_from_utc(+1, 12.0)
-        13.0
-
-        >>> time_from_utc(-1, 12.0)
-        11.0
-
-        >>> time_from_utc(+6, 6.0)
-        12.0
-
-        >>> time_from_utc(-7, 6.0)
-        23.0
-
-        >>> time_from_utc(-1, 0.0)
-        23.0
-
-        >>> time_from_utc(-1, 23.0)
-        22.0
-
-        >>> time_from_utc(+1, 23.0)
-        0.0
-    */
+	double result = time + utc_offset;
+	result = std::fmod(result, 24.0);
+	if (result < 0) {
+		result += 24.0;
+	}
+	return result;
+}
+
+int main()
+{
+	assert(std::fabs(seconds_difference(1800.0, 3600.0) - 1800.0) <= DBL_EPSILON);
+	assert(std::fabs(seconds_difference(3600.0, 1800.0) - (-1800.0)) <= DBL_EPSILON);
+	assert(std::fabs(seconds_difference(1800.0, 2160.0) - 360.0) <= DBL_EPSILON);
+	assert(std::fabs(seconds_difference(1800.0, 1800.0) - 0.0) <= DBL_EPSILON);
+
+	assert(std::fabs(hours_difference(1800.0, 3600.0) - 0.5) <= DBL_EPSILON);
+	assert(std::fabs(hours_difference(3600.0, 1800.0) - (-0.5)) <= DBL_EPSILON);
+	assert(std::fabs(hours_difference(1800.0, 2160.0) - 0.1) <= DBL_EPSILON);
+	assert(std::fabs(hours_difference(1800.0, 1800.0) - 0.0) <= DBL_EPSILON);
+
+	assert(std::fabs(to_float_hours(0, 15, 0) - 0.25) <= DBL_EPSILON);
+	assert(std::fabs(to_float_hours(2, 45, 9) - 2.7525) <= DBL_EPSILON);
+	assert(std::fabs(to_float_hours(1, 0, 36) - 1.01) <= DBL_EPSILON);
+
+	assert(std::fabs(to_24_hour_clock(24) - 0.0) <= DBL_EPSILON);
+	assert(std::fabs(to_24_hour_clock(48) - 0.0) <= DBL_EPSILON);
+	assert(std::fabs(to_24_hour_clock(25) - 1.0) <= DBL_EPSILON);
+	assert(std::fabs(to_24_hour_clock(4) - 4.0) <= DBL_EPSILON);
+	assert(std::fabs(to_24_hour_clock(28.5) - 4.5) <= DBL_EPSILON);
+
+	assert(get_hours(3800) == 1);
+	assert(get_minutes(3800) == 3);
+	assert(get_seconds(3800) == 20);
+
+	assert(std::fabs(time_to_utc(+0, 12.0) - 12.0) <= DBL_EPSILON);
+	assert(std::fabs(time_to_utc(+1, 12.0) - 11.0) <= DBL_EPSILON);
+	assert(std::fabs(time_to_utc(-1, 12.0) - 13.0) <= DBL_EPSILON);
+	assert(std::fabs(time_to_utc(-11, 18.0) - 5.0) <= DBL_EPSILON);
+	assert(std::fabs(time_to_utc(-1, 0.0) - 1.0) <= DBL_EPSILON);
+	assert(std::fabs(time_to_utc(-1, 23.0) - 0.0) <= DBL_EPSILON);
+
+	assert(std::fabs(time_from_utc(+0, 12.0) - 12.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(+1, 12.0) - 13.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(-1, 12.0) - 11.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(+6, 6.0) - 12.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(-7, 6.0) - 23.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(-1, 0.0) - 23.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(-1, 23.0) - 22.0) <= DBL_EPSILON);
+	assert(std::fabs(time_from_utc(+1, 23.0) - 0.0) <= DBL_EPSILON);
+
+	std::cout << "Tests completed\n";
+	return 0;
 }