clock_hands_angle_diff.cc

#include <assert.h>

// Angle from 0000 hrs
int hour_hand_angle(int hour, int min)
{
    return hour * 30 + min / 2;
}

// Angle from 0000 hrs
int min_hand_angle(int hour, int min)
{
    return min * 6;
}

int diff(int hour, int min)
{
    int tmp = hour_hand_angle(hour, min) - min_hand_angle(hour, min);
    tmp = tmp < 0 ? -tmp : tmp;

    return (tmp > 180) ? 360 - tmp : tmp;
}

int main()
{
    assert(hour_hand_angle(3, 0) == 90);
    assert(hour_hand_angle(9, 30) == 285);

    assert(min_hand_angle(10, 30) == 180);
    assert(min_hand_angle(9, 15) == 90);

    assert(diff(10, 16) == 148);
    assert(diff(2, 20) == 50);

    return 0;
}