Shuffle array elements

sashapont1 over 8 years ago

I have array of objects

array=[a1,a2,a3...a10]

How I can shuffle array elements by monkey с?

jim_m_58 over 8 years ago

You could use Math.rand()%10 to generate indexes, and then swap them.

travis.vitek over 8 years ago

Not that this is difficult to write, but I have code for this at home. I'll post it here tonight.

travis.vitek over 8 years ago

using Toybox.Math as Math

using Toybox.Test as Test;



//! shuffles `array' in place using Math.rand()

function shuffle(array) {

    var n = array.size();

    for (var i = n - 1; 0 < i; --i) {

        var j = Math.rand() % (i + 1);



        var tmp = array;

        array= array[j];

        array[j] = tmp;

    }

}



// helper test function

function do_test_shuffle(logger, a, b)

{

    shuffle(a);



    var a_size = a.size();

    var b_size = b.size();

    Test.assertEqual(a_size, b_size);



    for (var i = 0; i < a_size; ++i) {

        Test.assertEqual(a, b);

    }

}



(:test) function test_shuffle(logger) {



    Math.srand(0xdeadbeef);



    do_test_shuffle(logger, [],

                            []);

    do_test_shuffle(logger, [ 1 ],

                            [ 1 ]);

    do_test_shuffle(logger, [ 1, 2 ],

                            [ 1, 2 ]);

    do_test_shuffle(logger, [ 1, 2, 3 ],

                            [ 1, 2, 3 ]);

    do_test_shuffle(logger, [ 1, 2, 3, 4 ],

                            [ 4, 3, 2, 1 ]);

    do_test_shuffle(logger, [ 1, 2, 3, 4, 5 ],

                            [ 5, 2, 4, 3, 1 ]);

    do_test_shuffle(logger, [ 1, 2, 3, 4, 5 ],

                            [ 1, 2, 4, 5, 3 ]);

    do_test_shuffle(logger, [ 1, 2, 3, 4, 5 ],

                            [ 3, 2, 1, 5, 4 ]);

    do_test_shuffle(logger, [ 1, 2, 3, 4, 5 ],

                            [ 1, 4, 5, 2, 3 ]);



    return true;

}

[/code]