Solution Code for the Clock Problem

#include <bits/stdc++.h>  // Includes all standard libraries - useful for contests.

using namespace std;

int main()
{
    string input;
    double hour, minute;
    char colon;

    // Sets the precision.
    cout << fixed << setprecision(3);

    while (true)
    {
        // Handle the input.
        cin >> hour >> colon >> minute;

        // 0:00 should trigger a program termination.
        if (hour == 0 && minute == 0)
        {
            return 0;
        }

        if (hour == 12)
        {
            hour = 0;
        }

        // Convert the hours and minutes into angles.
        hour *= 30;
        hour += ((minute / 60) * 30);
        minute *= 6;

        // We can't just get the absolute difference as one hand might be at
        // 350 degrees while the other is at 10 degrees. The expected result would
        // be 20 degrees, but abs(350 - 10) is 340.
        // To fix this, we need to measure the reflex angle.
        // We can do this by checking if subtracting abs(350 - 10) from 360 makes
        // it smaller.
        cout << min(abs(hour - minute), 360.0 - abs(hour - minute)) << endl;
    }

    return 0;
}