Fuzzy Sort Algorithm Combines Stability

Question

Context

I perform a psychological test in which the user is presented with pairs of images that should indicate which they prefer. They respond to their preference either with the A key or with L. If the number of images is large enough, then comparing all possible pairs requires the individual (O (n ^ 2)).

Question

I hacked a merge sort algorithm here to significantly reduce the number of comparisons. The result is the following:

function mergeSort(arr)
{
    if (arr.length < 2)
        return arr;

    var middle = parseInt(arr.length / 2);
    var left   = arr.slice(0, middle);
    var right  = arr.slice(middle, arr.length);

    return merge(mergeSort(left), mergeSort(right));
}


function merge(left, right)
{
    var result = [];

    while (left.length && right.length) {
        if (getUserPreference(left[0],right[0])) {
            result.push(left.shift());
        } else {
            result.push(right.shift());
        }
    }

    while (left.length)
        result.push(left.shift());

    while (right.length)
        result.push(right.shift());

    return result;
}

getUserPreference . ( "" ~ 1/3 , "" , ), , -, :

• ().
• . ~ 20 10 .

, , - , whizzkids , , .

Answer 1

, ?

. , , // .

. ~ 20 10 .

10 15 , - 25 . merge sort O(n log n) .

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