function assertEqual(a, b) {
    /* Hackish function for stupid comparison number, strings and arrays */

    if (a.toString() != b.toString()) {
        alert(a + ' != ' + b);
    }
}

function find_distance(a, b) {
    /* Find distance between a and b не учитывая замкнутость координат на сфере */

    if ((a * b) > 0) {
        return Math.abs(a - b)
    } else {
        return Math.abs(a) + Math.abs(b)
    }
}

function find_clockwise_distance(a, b) {
    /* Find shortest distance between a and b учитывая замкнутость координат на сфере */

    if (a < b) {
        return b - a
    } else {
        return find_distance(a, 180) + find_distance(-180, b);
    }
}

/*
function find_real_distance(distance) {
    return Math.abs(Math.min(distance, 360 - distance)) 
}

function test_find_real_distance() {
    assertEqual(find_real_distance(10), 10)
    assertEqual(find_real_distance(180), 180)
    assertEqual(find_real_distance(190), 170)
}
*/

function find_min_distance(points) {
    /*
      Find the start and end points between all other points are placed and
      distance is minimal 
      Return start, end and distance
     */

    distance = 360
    start = null
    end = null

    points.sort(function(a, b) { return a - b; })

    for(x = 0; x < points.length; x++) {
        if (x == 0) {
            prev = points.length - 1
        } else {
            prev = x - 1
        }
        test_distance = find_clockwise_distance(points[x], points[prev])
        if (test_distance < distance) {
            distance = test_distance
            start = points[x]
            end = points[prev]
        }
    }
    return [start, end, distance]
}


function test_min_distance() {
    assertEqual(find_min_distance([10, 20]), [10, 20, 10])
    assertEqual(find_min_distance([10, -10]), [-10, 10, 20])
    assertEqual(find_min_distance([170, -170]), [170, -170, 20])
    assertEqual(find_min_distance([-170, 170]), [170, -170, 20])
    assertEqual(find_min_distance([-170, 160, 170]), [160, -170, 30])
    assertEqual(find_min_distance([-10, 10]), [-10, 10, 20])
}


function test_find_clockwise_distance() {
    assertEqual(find_clockwise_distance(10, 20), 10)
    assertEqual(find_clockwise_distance(20, 10), 350)
    assertEqual(find_clockwise_distance(10, -20), 330)
    assertEqual(find_clockwise_distance(-20, 10), 30)
    assertEqual(find_clockwise_distance(-20, -30), 350)
    assertEqual(find_clockwise_distance(-40, -30), 10)
}

    
function test_find_distance() {
    assertEqual(find_distance(10, 20), 10)
    assertEqual(find_distance(-10, 20), 30)
    assertEqual(find_distance(20, -10), 30)
    assertEqual(find_distance(-10, -50), 40)
    assertEqual(find_distance(0, 5), 5)
    assertEqual(find_distance(0, -5), 5)
}

function run_tests() {
    test_find_distance();
    test_find_clockwise_distance();
    test_min_distance();
}