Sort An Array With Item Closest To Two In Middle And Other Extremes On Other Side - Js

I have 3 numbers in an array that I want to order so that the item closest to 2 is in the middle, the lowest from two on the left and the highest from two on the right. example 1 -

Solution 1:

You need a three step approach, first sort to get the closest to the given value, shift that value and sort the rest ascending. Then plice the temporary value to index 1.

functionsort(array) {
    var temp = array.sort((a, b) =>Math.abs(x - a) - Math.abs(x - b)).shift();
    array.sort((a, b) => a - b).splice(1, 0, temp);
    return array;
}

var x = 2;
console.log(sort([0, 1, 2]));
console.log(sort([1, 2, 3]));
console.log(sort([2, 3, 4]));

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Another solution would be to collect the values with bigger delta in a new array and sort it. Later put the reduced value back to index 1.

Advantage: No superfluous sort, while only one iteration is needed.

functionsort(array) {
    var temp = [],
        value = array.reduce((a, b) =>Math.abs(x - a) < Math.abs(x - b) ? (temp.push(b), a) : (temp.push(a), b)
        );

    temp.sort((a, b) => a - b).splice(1, 0, value);
    return temp;
}

var x = 2;
console.log(sort([0, 1, 2]));
console.log(sort([1, 2, 3]));
console.log(sort([2, 3, 4]));

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Solution 2:

To easy, sort after distance to 2, then put the first into the second position:

arr.sort((a,b)=>Math.abs(a-2)-Math.abs(b-2));

arr=[arr[1],arr[0],arr[2]];

http://jsbin.com/kifitosopo/edit?console

Solution 3:

You could do it using one reducer with straight forward rules.

constdiff = value => Math.abs(value - 2)

constsort = arr => arr.reduce(([min, closest, max], value) => {
    if(closest !== closest || diff(value) < diff(closest)) [closest, value] = [value, closest]

    if(min !== min || value < min ) min = value
    
    if(max !== max || value > max ) max = value
    
    return [min, closest, max]
    
  }, newArray(3).fill(NaN))


const tests = [
  [2.3, 5.2, 1.2],
  [1.1, 2.3, 0.3],
  [1.3, 0.3, 2],
  [2.2, 2.3, 2.1] 
]

tests.forEach(test =>console.log(`[${test.join(', ')}] --> [${sort(test).join(', ')}]`))